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MANUAL OF VEGETABLE-GARDEN INSECTS 



Ube IRural /iDauuals 

Edited by L. II. BAILEY 

Manual of Gardening — Bailey 

Manual of Farm Animals — Harper 

Farm and Garden Rule-Book — Bailey 

Manual of Fruit Insects — Slingerland and Crosby 

Manual of Weeds — Georgia 

The Pruning-Manual — Bailey 

Manual of Fruit Diseases — Hesler and Whetzel 

Manual of Milk Products — Stocking 

Manual of Vegetable-Garden Insects — Crosby 

and Leonard 
Manual of Tree Diseases — Rani in 
Manual of Home-Making — Van Rensselaer, Rose, 

and Canon 



MANUAL OF 

VEGETABLE-GARDEN INSECTS 



BY 

CYRUS RICHARD ^ROSBY 

AND 

MORTIMER DEMAREST LEONARD 

OF THE NEW YORK STATE COLLEGE OF AGRICULTURE 
AT CORNELL UNIVERSITY 



THE MACMILLAN COMPANY 

1918 

All riglitt) resei^ved 









COPTEIQHT, 1918, 

bt the macmillan company. 



Set up and electrotyped. Published September, igi8. 



J. S. Gushing Co. — Berwick & Smith Co. 
Norwood, Mass., U.S.A. 



'CI.Af)0H209 



Co 

JAMES FLETCHER 

STUDENT AND TEACHER 

FOR A (ilAiriKK OF A CENTIHY 
ENTOMOLOGIST AND 150TANIST TO TIIK DOMINION OF CANADA, 

NOTED 

FOK HIS STUDIES IN ECONOMIC ENTOMOLOGY 

AND FOK THE CLEARNESS AND ACCURACY OF THE 

PRESENTATION OF HIS WORK TO THE PUBLIC 

AND ENDEARED TO THE YOUNGER GENERATION OF WORKERS 

BY HIS KINDLY INTEREST AND ENCOURAGEMENT, 

THIS BOOK IS DEDICATED AS A TOKEN 

OF THE authors' ESTEEM 



PREFACE 

In the present work we have attempted to bring together in 
concise and usable form what is known in regard to the habits, 
hfe history and control of the insect enemies of vegetable-garden 
crops in the United States and Canada. Much of this infor- 
mation has been published in technical journals and in the 
bulletins and circulars of the State Experiment Stations and 
Federal Government, where it is available only to the special 
student who has access to the few large libraries that collect 
and preserve this type of literature. We ha\e endeavored 
thoroughly to digest this mass of material and present it in a 
form adapted to the needs of the gardener and vegetable- 
grower. 

In regard to methods of control we have tried to eliminate 
as far as possible useless and imjiracticable recommendations 
and include only those found to be effective under commercial 
conditions or such as would seem to be worthy of trial. It has 
seemed better to state frankly that the problem of control in 
certain cases has not been solved than to suggest remedies that 
would lead to disappointment. 

The chapter on cutworms and the accounts of several others 
of the lepidoptera were M'ritten in collaboration with Dr. 
Robert Matheson. We are under great obligation to Dr. W. T. 
INI. Forbes for criticism and aid with the lepidoptera ; to Dr. 

E. C. Van Dyke for the determination of beetles ; to jNlr. Charles 

vii 



viii PREFACE 

W. Leiig for the gift of specimens ; to S. W. Frost for the use 
of photographs ; and to many others for similar favors. 

The drawings were made by Anna C. Stryke, Ellen Edmonson, 
Nellie H. Crosby and C. H. Kennedy. Several of the illustra- 
tions are from photographs previously published in bulletins 
b\- the late Prof. M. V. Slingerland, by Prof. G. W. Herrick and 

by H. H. Knight. 

C. R. Crosby. 

M. D. Leonard. 

Cornell University, Ithaca, N. Y. 
May 28, 1918. 



CONTENTS 



CHAPTER I 



General Considerations 



PAGE 
1 



CHAPTER II 

Insects Injurious to Cabbage and Related Crops 
Imported cabbage worm 
Potherb butterfly 
Southern cabbage liutterfly 
Cabbage looper . 
Diamond-back moth 
Cross-striped cabbage worm 
Cabbage webworm 
Garden webworm 
Purple-backed cabbage 
Zebra caterpillar . 
Cabbage aphis 
Turnip aphis 
Cabbage root-maggot 
Seed-corn maggot 
Western radish 'maggot 
Harlequin cabbage bug 
Green soldier-bug 
Cabbage leaf-miners 
False chinch-bug . 
Cabbage eurculio . 
Cabbage seed-stalk weevil 
Red turnip beetle . 
Other insects injurious to cabbage and related crops 



4 
7 
7 
9 
12 
14 
IG 
18 
19 
21 
22 
27 
29 
3G 
37 
38 
42 
43 
47 
49 
50 
50 
51 



CHAPTER III 

Pea and Bean Insects 54 

Pea wee\il .......... 54 

Bean wee^al 57 

Broad bean weevil ........ 60 

ix 



CONTENTS 



Four-spotted bean weevil 

Cowpea weevil 

Bean leaf-beetle 

Grape colaspis 

Bean ladybird 

Bean thrips . 

Pea aphis 

Bean aphis . 

Garden flea-hopper 

Pea moth 

Bean leaf-roller 

Striped green bean caterpillar 

Gray hair-strealc . 

Green clover worm 

Lima bean vine-borer . 

Other pea and bean insects 



CHAPTER IV 



Beet and Spinach Insects 
Spinach leaf-miner 
Beet leafhopper . 
Larger sugar-beet leaf-beetle 
Western beet leaf-beetle 
Sugar-beet webworm . 
Hawaiian beet Avebworm 
Spotted beet webworm . 
Southern beet webworm 
Sugar-beet root-louse . 
Spinach aphis 
Other beet and spinach insects 



CHAPTER V 

Insects Injuriotts to Cucumber, Squash and Melon 
Striped cucumber beetle 
Western cucumber beetle 
Twelve-spotted cucumber beetle 
Western twelve-spotted cucumber beetle 
Belted cucumber beetle 
Squash bug ..... 



CONTENTS 



XI 



Horned squash bug 

Melon Icai'-hug 

Southern leaf-footed i)lant-l)Uf; 

Northern leaf-footed plant-bu^ 

Squash-vine borer 

Pickle worm 

Melon worm 

Squash ladybird . 

Melon aphis 

Squash aphis 

Garden springtail 

Other cucumber, squash and melon insects 



CHAPTER VI 



Potato Insects 

Colorado potato beetle 
Three-lined potato beetle 
Potato aphis 
Apple leafhoppcn* 
Potato stalk-weevil 
Common stalk-borer 
Burdock borer 
Potato scab gnat 
Potato tuber moth 
Other potato insects 



CHAPTER VII 



Tomato Insects 
Tomato worms 
Tomato stilt-ljug . 
Eastern field wireworm 
Erinose of the tomato 
Other tomato insects 



CHAPTER VIII 



Ecgplant Insects 



Eggplant tortoise beetle 
Eggplant lace-bug 
Other eggplant insects . 



177 
177 

178 
179 



Xll 



CONTENTS 



CHAPTER IX 

PAGE 

Insects Injurious to Carrot, Celery, Parsnip and Related 

Crops . . 181 

Carrot riist-fly ......... 181 

Carrot beetle . . . . . . . . . 185 

Black swallow-tail butterfly ...... 18G 

Celery leaf-tycr 189 

Celery looper . . . . . . . . .191 

Tarnished plant-bug . . . . . . . . 192 

Negro-bug .......... 196 

Parsnip webworni . . . . . . . .197 

Parsnip leaf-miner ........ 199 

Parsley stalk-weevil ........ 199 

Other carrot, celery and parsnip insects .... 200 



CHAPTER X 

Asparagus Insects . 

(yommon asparagus beetle . 
Twelve-spotted asparagus beetle . 
Asparagus miner 
Other asparagus insects 



201 
201 
205 
208 
210 



CHAPTER XI 



Corn Insects . 
Corn ear-worm 
Corn root-aphis . 
Southern corn root-worm 
Western corn root-worm 
Colorado corn root-worm 
Larger corn stalk-borer 
Lesser corn stalk-borer 
Brown fruit-chafer 
Stink-bugs . 
Other corn insects 



211 
211 
218 
222 
225 
227 
228 
229 
231 
232 
233 



CHAPTER XII 

Sweet Potato Insects ......... 235 

Tortoise beetles . . . . . ' . . . . 235 

Sweet potato weevil ........ 239 



CONTENTS 



Xlll 



Sweet potato leaf-roller 
Sweet potato white-fly 
Other sweet potato insects 



CHAPTER XIII 



Onion Insects 

Onion maggot 
Onion thrips 
Barred-winged onion fly 
Black onion fly 
Other onion insects 



PAGE 

241 
242 
242 



CHAPTER XIV 

Insects Injurious to Minor Vegetahli 
Rhubarb 
Okra . 
Salsify 
Pepper 
Water-eress . 
Lettuce 

CHAPTER XV 

Cutworms and Army-worms 
Spotted ciitworm 
Well-marked cutworm 
Greasy cutworm . 
Red-backed cutworm 
Dark-sided cutworm 
Striped cutworm . 
Dingy cutworm . 
Shagreened cutworm 
Granulated cutworm 
Clay-backed cutworm 
Black army cutworm 
Variegated cutworm 
White cutworm . 
Glassy cutworm . 
Yellow-headed cutworm 



Crops 



XIV 



CONTENTS 



Spotted-legged cutworm 

Speckled cutworm 

Clover cutworm . 

Bristly cutworm . 

Bronzed cutworm 

Army cutworm 

Army-worm . 

Fall army- worm . 

Beet army-worm . 

Yellow-striped army-worm 

Semi-tropical army-worm 

Other cutworms . 

Control of cutworms and army-worms 



CHAPTER XVI 

Blister-Beetles 

Striped blister-beetle . 
Margined blister-beetle 
Gray blister-beetle 
Ash-gray blister-beetle 
Black blister-beetle 
Nuttall's blister-beetle 
Spotted blister-beetle . 
Two-spotted blister-beetle 
Miscellaneous ])lister-beetles 
Means of controlling blister-beetles 



CHAPTER XVII 



Flea-Beetles 

Potato flea-beetle 
Western potato flea-beetle 
Tobacco flea-beetle 
Eggplant flea-beetle 
Pale-striped flea-beetle 
Red-headed flea-beetle 
Smartweed flea-beetle . 
Striped cabbage flea-beetle 
Sinuate-striped flea-beetle 
Western cabbage flea-beetle 



CONTENTS 



XV 



Horse-radish flea-beetle 
Spinach flea- beetle 
Yellow-neeked flea-beetle 
Three-spotted flea-beetle 
Larger striped flea-beetle 
Sweet potato flea-beetle 
Desert corn flea-beetle . 
Hop flea-boetle 
Means of controlling: flea-beetles 



PAGE 

328 
329 
331 
331 
332 
332 
334 
335 
336 



CHAPTER XVIII 



Unclassified Pests 



Root-knot nematode 
Sugar-beet nematode . 
Millipedes . 
White gi'ubs . 
Wireworms . 
Grasshoppers 
Red-spider . 
Slugs . . . . 
Yellow bear caterpillar . 
Salt-marsh caterpillar . 



338 
338 
342 
342 
344 
347 
350 
351 
354 
357 
359 



CHAPTER XIX 



Insects and Insecticides 
Structure of insects 
Insecticides 



361 
361 
368 



MANUAL OF VEGETABLE- 
GARDEN INSECTS 

CHAPTER I 
GENERAL CONSIDERATIONS 

It was estimated by C. L. Marlatt in 1909 that the annual 
loss caused to vegetable and truck crops in the United States 
by insect pests amounts annually to 20 per cent of their value, 
or $68,000,000. This sum includes the cost of insecticides and 
other expense incurred in fighting vegetable insects. 

Insects affect vegetable crops in various ways. They feed 
on the leaves, devour the roots, tunnel the stems and infest 
the seeds and fruits. In many cases their injuries to succulent 
parts of the plant give entrance to decay-producing organisms 
which greatly augment the damage. Insects also act as carriers 
of specific diseases, the most remarkable instances of this kind 
being the transmission of the curly-leaf disease of the beet b}' 
the beet leaf-hopper and the carrying over winter of the bacterial 
wilt of cucurbits by the striped cucumber beetle. 

The enemies of vegetables here treated are, with five excep- 
tions, members of that class of animals known as insects. These 
exceptions are : the red-spider and the mite producing erinose 
of the tomato, which are Arachnids ; snails or slugs, belonging 
to the molluscs; millipedes belonging to the Myriapoda and 
the root-knot nematode, one of the true worms. 

Some vegetable insects are general feeders, attacking a great 
variety of plants, but the greater number are more or less 

B 1 



2 MANUAL OF VEGETABLE-GARDEN INSECTS 

restricted to a single family or (jtlier closely related group of 
plants, both wild and cultivated. Thus many beet insects 
also feed on weeds belonging to the goosefoot family, cabbage 
insects on weeds of the mustard family, potato insects on wild 
solanaceous plants and sweet potato insects on wild morning- 
glories. This fact, that certain insects form more or less 
definite associations with certain groups of plants, is of great 
practical importance and must be kept in mind when considering 
methods of preventing injury. It also explains why clean farm- 
ing is one of the most important factors in preventing insect 
injuries to vegetable crops. In fact, clean farming together 
with proper cultural practices often makes it unnecessary to re- 
sort to special remedial measures, or at least renders it possible 
to obtain more effective results from the use of insecticides. 

About 250 species of insects have been recorded as serious 
enemies of vegetable crops in the United States and Canada but 
a much larger number may occasionally become injurious. 
Only the more important species are treated in the following 
chapters, arranged under the crops to which they are most 
injurious. Flea-beetles, blister-beetles, cutworms and other 
general feeders are discussed in separate chapters. 



CHAPTER II 

INSECTS INJURIOUS TO CABBAGE AND RELATED 

CROPS 

L\ this chapter are treated the more important insect enemies 
of cabbage, cauliflower, brussels sprouts, kohlrabi, kale, col- 
lards, radish, turnip, mustard and horse-radish. With the 
exception of horse-radish, these form a natural group of food 
plants that serves as the common host for a large number of 
insects, which, although showing a preference for certain crops, 
can also thrive on the others. ]\lany cruciferous weeds are 
also food plants of these pests and may serve as centers of in- 
festation from which the insects spread to cultivated crops. 
The most important enemies of cabbage and related crops in 
this country have been imported from the Old World but some 
of the native insects have found in these succulent vegetables 
satisfactory food plants. Of European origin are the cabbage 
root-maggot, the common cabbage worm, the diamond-back 
moth, the cabbage aphis, the cabbage curculio and the cabbage 
seed-stalk weevil. The cabbage webworm had its original 
home in the Old World tropics and the harlequin cabbage bug 
spread into the United States from Central America during the 
last half century. 

Horse-radish has relatively few insect enemies, the most 
important being the harlequin cabbage bug and the horse- 
radish flea-beetle. 

Cabbage and related crops are often seriously injured by cut- 
worms and flea-beetles. These insects are treated in Chapters 
XV and XVn. 

3 



4 MANUAL OF VEGETABLE-GARDEN INSECTS 

The Imported Cabbage Worm 

Pontia ra-pcc Linnaeus 

The common white cabbage butterfly of the United States 
and Canada is a native of the Old World. It was first intro- 
duced into America at Quebec about 1860. Later independent 
introductions occurred at New York in 1868, at Charleston, 
South Carolina, in 1873 and at Apalachicola, Florida, at about 
the same date. From these points as centers the insect spread 
rapidly and by 1885 it occupied practically the whole territory 
east of the Pacific slope. The favorite food plant of the im- 
ported cabbage worm is cabbage, but it also attacks cauli- 
flower, turnip, horse-radish, radish, mustard, gillyflower, 
nasturtium and sweet alyssum and it also feeds on a number of 
wild plants belonging to the mustard family. The cater- 
pillars are sometimes found abundantly on mignonette. 

The imported cabbage worm hibernates in the pupal state 
and the white butterflies emerge in early spring, being among 
the first to appear in our fields and 
meadows. Their flight is low and 
unsteady and they alight at frequent 
intervals. The female deposits her eggs 
singly on the under surface of the leaves 
of the food plant. The egg (Fig. 1) is 
lemon yellow in color, nearly -^ inch 
Fig. 1- Eggs of tl.e im- j^ j^ ^j^ ^^^ attached to the leaf at 

ported cabbage butter- ^ 

fly (X 15). one end. It is broadest two thirds 

of the distance from the base, and 
then tapers tn the top, which is flattened. The surface is beau- 
tifully ridged lengthwise and crosswise. The egg hatches in 
about a week and the pale greenish yellow caterpillar begins 
feeding on the under surface of the leaf, which it skeletonizes. 
A little later the caterpillars are able to eat out holes in the 
leaves, only the larger veins remaining. When the plants are 




INJURIOUS TO CABBAGE AND RELATED CROPS 




. _'. — I iill-gi'i >\\ II iiiii"irtfil 
(;ubbage worm (, X IJ)- 



headin*;, tlie caterpillars (iften burrow rather deeply into the 

head in search of the tenderest leaves. They become full 

grown in ten to fourteen days. 

The mature caterpillar (Fig. 2) is 

about an inch in length, velvety 

green in color and marked with a 

greenish yellow stripe down the 

back and an interrupted one on 

each side. When ready to pupate, 

it seeks some sheltered place — ■ 

under a cabbage leaf or on the underside of fence boards — 

in which to transform to the chrysalis. When a cabbage 

patch is near a house, these 
chrysalids are often found in 
great numbers under the edge of 
the clapboards. When about to 
transform, the caterpillar first 
spins a carpet of silk over the 
surface chosen and fastens a deli- 
cate silken girdle around its 
body at the first abdominal seg- 
ment, holding itself tightly in position (Fig. 3). After the 

transformation is complete the chrysalis is" held in place by 

this girth. The pupa (Fig. 4) 

is about f inch in length and 

of a pale green or yellowish 

browm color. Except in the 

case of those chrysalids which 

winter over, transformation to 

the butterfly takes place in a 

week to twelve days. The 

butterfly has an expanse of 

about If inches. The wings are nearly white in ground color 

often more or less suffused with yellowish. The tip of the 




Fig. 3. — Imported cabbage worm 
suspended for pupation (X 1^). 




Fig. 4. — Chrysalis of imported 
cabbage worm (X 25). 



MANUAL OF VEGETABLE-GARDEN INSECTS 




front wing is grayish ; there are two 
l)hick spots on the front wing of the 
female and one in the male and in 
both sexes there is a black spot near 
the front margin of the hind wing 
(Fig, 5). Spruig males are smaller 
and sometimes unspotted. In New 
England the cabbage butterfly has 
three broods annually and in the 
South there are said to be six. 



Co)itrol. 

Cabbage worms may be easily 
killed by spraying with paris green, 
1 pound in 50 gallons of water, or 
arsenate of lead (paste), 4 pounds in 50 gallons of Avater. 
The first application should be made soon after the plants 
are set out and repeated whenever the worms become numer- 
ous. The poison may be applied in the form of a dust diluted 
with some inert material, such as flour, plaster or hydrated 
lime, but is not so effective wdien used in this way. Chemical 
analysis of sprayed plants has shown that there is practically 
no danger from eating cabbages that have been treated wuth 
an arsenical. In the home garden jtyrethrum, hellebore or hot 
water (130° F.) will be found convenient remedies. When only 
a few plants are grown, hand-picking is often the cheapest and 
easiest way of destroying the worms. 



Fiu. 5. — The imported cab- 
bage worm butterflies, male 
above, female below ( X f). 



References 



Scudder, Butterflies of Eastern U. S., 2, pp. 1175-1190; 1205-1218. 

1889. 
U. S. Bur. Ent. Giro,. 60. 1905. 
U. S. Farm. Bull. 766. 1916. 



INJURIOUS TO CABBAGE AND RELATED CROPS 



The Potherb Butterfly 

Ponlia oleracen Harris 

Before the introduction of the imported cabbage butterfly, 
this species was abundant in the northern I'nited States and 
Canada east of the Rocky INIoun- 
tains but soon became rare 
throughout the greater part of its 
range. The caterpillar of this 
species closely resembles that of 
the imported form but lacks the 
yellowish dorsal stripe. The 
butterfly has the upper surface 
of both i)airs of wings and the 
under surface of the front wings 
nearly pure white. The hind wings arc usually marked (jn 
the underside with gray stripes extending along the veins. 
Rarely the under surface is pure white (Fig. 6). 




Fig. 6.- 



■ The potherb butter- 
fly (X f). 



References 

Riley, U. S. Ent. Rept. for 1883, pp. 115-117. 
Scudder, Butterflies of Eastern U. S., 2, pp. 1191-1204. 



1889. 



The Southern (\\bba(;e Butterfly 
Pontia protodice Boisduval and Le Conte 

This cabbage-feeding caterpillar is widely distributed through- 
out the United States but is more common southward, where it 
often causes serious injury to cruciferous crops. As in the 
case of the potherb butterfly, this species has decreased in 
numbers and importance since the introduction of its European 
relative. The butterfly is known as the checkered white. The 
ground color of the wings is white in the male and dirty white in 



MANUAL OF VEGETABLE-GARDEN INSECTS 



the female and the upper side of 
the fore wings in both sexes is 
marked with several black spots 
(Fig. 7). The caterpillar is about 
an inch in length, purplish green 
in color marked with four longi- 
tudinal greenish yellow stripes and 
covered with small black dots. 

The last two species may be con- 
trolled by the same measures as 
recommended for use against the imported cabbage worm. 




Fig. 7. — The southern cab- 
bage butterfly, male ( X f ) . 



References 

Riley, U. S. Ent. Rept. for 1883, pp. 114-115. 

Scudder, Butterflies of Eastern U. S., 2, pp. 1163-1170. 1889. 



The Cabbage Looper 

Autographa brassicce Riley 

This well-known cabbage pest is a native American insect 
widely distributed throughout the United States and occurring 
as far south as Mexico. In some localities, especially in the 
South, it is the most serious insect with which the grower 
of late cabbage and cauliflower has to contend. In addition to 
cruciferous plants such as cabbage, kale, cauliflower and 
turnip, the cabbage looper may also occasionally cause serious 
injury to lettuce, celery, beet, pea and parsley. It also feeds 
on tomato, potato, asparagus, dandelion and dock and some- 
times attacks carnation and mignonette in greenhouses. On 
Long Island it is especially injurious to late cauliflower and to 
lettuce that has been transplanted from coldframes into the 
forcing houses. 

The insect as a rule passes the winter in the pupal stage, 
although it is not improbable that occasionally some of the 



INJURIOUS TO CABBAGE AND RELATED CROPS 9 




Fig. 8. — Erk "f 
the cabbage loopcr 
(X 10). 



later emerging moths may hibernate. In any case, only a 
relatively small number survive the winter and consequently 
the first brood of the season is small and causes comparatively 
little injury. The female moth 'deposits her small whitish 
eggs singly or in small groups usually on the 
upper side of the leaves. The egg (Fig. 8) 
is about -g-^ inch in diameter, pale greenish 
yellow or nearly white in color, nearly 
circular in outline and rounded above. The 
surface is beautifully marked with a series 
of ridges radiating from the apex. The 
length of the egg stage has not been deter- 
mined but it is probably not far from a week 
or ten days. The young larvpe are pale green 
in color and feed at first on the outer leaves of the cabbage; 
as they grow older, they become darker green and are marked 
with distinct white longitudinal lines. At this time they work 
in toward the center of the plant, and often bore into the form- 
ing head. The full-grown caterpillar (Fig. 9) is about 1^ 
inches in length. It is pale green in color with a white stig- 
matal stripe and two dorsal stripes extending the whole length 

of the body. On each side 
of the dorsal stripe there is 
a fine white line. The 
caterpillar is narrower in 
front and has the body en- 
larged toward the posterior 
end which is bluntly trun- 
cate. Although the cater- 
pillars are close relati\es of the cutworms, they crawl with a 
peculiar looping motion like the measuring-worms, due to no 
prolegs being present on the third and fourth abdominal 
segments. The caterpillars attain their growth in from 
two weeks to a month, depending on the temperature. 




Fig. 9. 



Full-grown cabbage looper 
(X If). 



10 



MANUAL OF VEGETABLE-GARDEN INSECTS 




When mature the caterpillar spins a light flimsy semi- 
transparent cocoon (Fig. 10) of white silk about Ij inches in 
length, usually on the underside of the leaf. It consists of 
two filmy layers, an inner one close to 
the pupa and an outer one connected 
with the other by many fine threads. 
Soon after completing its cocoon, the 
larva transforms to a dark brown or 
blackish pupa (Fig. 11) about f inch 
in length. The moth (Fig. 12) emerges 
Fig. 10. — Cocoon of the "^ ten days to two wecks ; it has a'n 
cabbage looper from expanse of l| to 1^ inches. The front 

which the moth has . 111 • i 1 • , 1 

emerged (xf). wmgs are dark brown variegated with 

lighter brown and bear near the center 
two silver spots, one oval and the other shaped like a con- 
stricted U. Sometimes these spots are united and resemble 
an imperfect figure 8. The hind wings are mouse-colored 
with bronze reflections in certain lights. 

There are said to be three broods of the insect annually on 
Long Island, New York, and four at Washington, D. C. As 
only a relatively small number 
of pupae survive the winter, the 
first brood caterpillars are gen- 
erally not abundant enough to 
cause much injury and are 
usually overlooked entirely. 
The succeeding broods increase 
rapidly in numbers and impor- 
tance, the last being the most 
destructive. Towards the end 
of the season, the broods over- 
lap so that all stages of the insect are present on the cabbage 
plants at the same time. 

The cabbage looper is held in check by several parasites and 




Fig. 11. — PupjE of the cabbage 
looper (X 2f). 



INJURIOUS TO CABBAGE AND RELATED CROPS 11 



by a disease. Diseased caterpillars at first turn yellowish and 
later take on an ashy hue (Fig. 13). They become inactive, 
stop feeding and soon die. After death the skin breaks open 
and the body contents 
which have become 
liquid oozes out and 
becomes smeared on 
the leaves. Sometimes 
a large proportion of 
the caterpillars are de- 
stroyed by this disease 
late in the season. 

Control. 

The cabbage looper 
is a difficult insect to 




Fig. 12. — Moth of the cabbage looper (X I3). 



poison because the caterpillars refuse to eat leaves coated 
with an insecticide and move quickly to some part of the 
plant that has been missed in spraying. Furthermore, it is 
not easy to spray a cabbage plant so as to cover all parts 

of the leaves, especially the 
underside of the outer leaves 
and those in the forming 
head. Experiments on Long 
Island have shown that good 
results may be obtained by 
thorough spraying with paris 
green, 1 pound in 80 gallons 
of water to which the resin- 
lime mixture has been added. Some growers dust the plants 
lightly with pure paris green and have reported satisfactory 
results from this treatment. 




Fig. 13. 



A diseased cabbage looper 
(Xli). 



12 MANUAL OF VEGETABLE-GARDEN INSECTS 



References 

Riley, U. S. Ent. Rept. for 1883, pp. 119-122. 

N. Y. (Geneva) Agi'. Exp. Sta. Bull. 83, pp. 667-671. 1894. 

N. Y. (Geneva) Agr. Exp. Sta. Bull. 144. 1898. 



The Diamond-Back Moth 

Pluiella maculipennis Curtis 

In this country the diamond-back moth is rarely more than a 
minor enemy of cabbage and related crops, but in some parts 
of its extensive range its injuries are of considerable importance. 
Apparently introduced from Europe some time before 1854, 
the insect is now widely distributed throughout the United 
States and Canada ; it also occurs in South America, Australia, 
New Zealand, South iVfrica, India, Greenland and Spitzbergen. 
It seems able to maintain itself wherever its food plants are 
grown, whether in the tropics or in the arctic region. In Eng- 
land the insect is also known as the turnip fly and in some parts 
of the United States it is called the shot-hole worm. Besides 
cabbage, cauliflower, brussels sprouts, rape, horse-radish, 
radish, kale, mustard, turnip and water cress, the insect attacks 
stocks, wall-flowers, sweet alyssum and candytuft. It some- 
times becomes very troublesome on these plants in green- 
houses. 

The diamond-back moth hibernates in the adult condition 
hidden away under the cabbage leaves left in the field. The 
moths appear in the spring as soon as food plants are available 
on which to deposit their eggs. The moth (Fig. 14) has an 
expanse of about f inch. In the male the front wings are ash- 
colored dotted with minute dark spots and have a yellow stripe 
outlined by a wavy dark line extending along the hind border. 
When the wings are closed, the united yellow stripes form a row 
of three diamond-shaped markings. In the female the front 
wings are a nearly uniform gray. The hind wings in both sexes 



INJURIOUS TO CABBAGE AND RELATED CROPS 13 




Fici. 14. 



^- 



The diamond-back moth, male 
(X3f). 




are dull gray. When at rest the moth has the wings slightly 
turned up at the tip and the antennae are held extended forward. 
The female moth deposits her minute whitish or yellowish eggs, 
Yi inch in diameter, singly or in groups of two or three, usually 
on the leaves. Each 
moth is capable of lay- 
ing on an average 
nearly 300 eggs during 
a period of one to two 
weeks. They hatch in 
three to six days and 
the young caterpillars 
first eat holes in the 
leaf from beneath but 
do not cut through to 
the upper surface. Later the upper epidermis dies, turns brown 
and drops out leaving the leaf riddled with holes. Sometimes 
in cool weather the young larvae li\^e as miners in the leaf for 
twf) to four days. The caterpillars are very active when dis- 
turbed, wriggle from the leaf and suspend themselves by a thread 
till the danger has passed. The larva reaches maturity in nine 

to twenty-eight days. 
It is then only about 
I inch in length, pale 
green in color and 
sparsely clothed with 
small, erect black hairs ; 

Fig. 15. ^Cocoon of the d.am,.nd-l,a.k moth the head is brOWnish 
showing the larva within (X 4). yclloW mottlcd with 

black. The larvae be- 
come mature in about a month and spin their beautiful open- 
work cocoons (Fig. 15), so loosely woven that the pupa can 
be plainly seen within, on the underside of the leaves. In 
the summer from four to thirteen days are spent in the pupal 




14 MANUAL OF VEGETABLE-GARDEN INSECTS 

stage. In the northern states there are two or three broods 
annually, which overlap to a considerable extent, but in the 
tropics breeding is almost continuous. In Colorado there are 
seven generations annually. On Long Island, larvte and moths 
are often abundant on cauliflower until early December. The 
insect is usually more destructive in dry seasons than when 
rains are abundant. On cabbage the greatest injury is usually 
inflicted early in the season while the plants are small, but in 
the case of cauliflower the late broods are the most troublesome. 
A closely related species, Plutella armoracia Busck, has been 
reported as injurious to horse-radish in Colorado. Its habits 
are similar to those of the diamond-back moth. 

Control. 

Experiments in Colorado have shown that the diamond- 
back moth can be controlled by spraying with 2 pounds of 
paris green and 6 pounds of soap in 100 gallons of water, or 
arsenate of lead (paste), 8 pounds in 100 gallons. 

Reference.s 

Fitch, 1st Rept. State Ent. N. Y., pp. 170-17.5. 1856. 
Carpenter, Rept. for 1901, pp. 144-147. 1902. 
Quanjer, Tijds. Ent. 49, pp. 11-17. 1906. 
Marsh, Jour. Agr. Research, 10, pp. 1-10. 1917. 

The Cross-Striped Cabbage Worm 

Evergestis rimosalis Guenee 

While widely distributed throughout the United States ex- 
cept in the extreme north, the cross-striped cabbage worm is 
most abundant and destructive in the southern states. Locally 
in some years it often causes more injury than the imported 
cabbage worm and its native relatives. The caterpillars 
destroy the leaves in much the same way as the common cab- 



INJURIOUS TO CABBAGE AND RELATED CROPS 15 



})age worm and have an especial fondness for the tender central 
leaves and forming head, often burrowing into the latter. In 
addition to cabbage and related crops, this insect has been 
reported as feeding on nasturtium in California. 

The insect hibernates in the pupal stage in a snug cocoon 
just below the surface of the ground. The moths emerge in 
early spring — in April in the District of Columbia. The 
moth (Fig. 16) has an expanse of about an inch. The front 
wings are pale ocher-yellow in color, marked with an indistinct 
zigzag brownish line and suffused with various shades of brown, 
darker towards the middle of the outer margin. The hind wings 
are nearly transparent towards the 
base, fuscous at the front angle and 
marked across the disk with a row 
of five or six small indistinct dusky 
spots. The female moth deposits 
her light yellow, rounded oval eggs 
about ^ inch in diameter, in cir- 
cular masses on the underside of 
the leaves. Each egg-mass con- 
tains twenty to thirty eggs which 
are flattened and overlap. They are semi-transparent and 
the green of the leaf shows through the mass. The eggs 
hatch in about six days and the young caterpillars begin 
feeding on the leaves, eating out long oval holes. The 
newly hatched larva is of a nearly uniform gray color. 
When full-grown it is about yu i'^ch in length, bluish gray 
above with distinct transverse black stripes, three or more to 
each segment. On the side a wide stigmatal line of bright 
yellow extends from the second to the last segment. Beneath, 
the caterpillar is green mottled with yellowish. In the summer 
the caterpillars reach maturity in about a month, but in the 
cooler months a somewhat longer period is required. When full- 
grown the caterpillar descends to the ground and just below 




Fig. 16. — The moth of the 
cross-striped cabbage worm 
(X If). 



IG MANUAL OF VEGETABLE-GARDEN INSECTS 

the surface constructs a tight cocoon into the outer surface 
of which bits of dirt and sand are incorporated. The cocoon 
is I inch in length by | inch in width. The pupa is f to ^ inch 
in length and has the head and wing-cases dark brown and the 
abdomen light yellowish brown. The summer broods of the 
insect spend about ten days in the cocoon but the time in the 
pupal stage has not been determined. It is probably about 
six days. There are supposed to be three generations annually. 
The cross-striped cabbage worm may be controlled by the 
measures suggested for the imported cabbage worm. 

Reference 
U. S. Div. Ent. Bull. 33, pp. 54-59. 1902. 

The Cabbage Webworm 

Hellula undalis Fabricius 

Originally a native of the tropical and subtropical regions 
of the Old World, the cabbage webworm was introduced into 
the southern United States shortly before 1895 and now ranges 
as far north as North Carolina and west to Oklahoma, Texas 
and southern California. It also occurs in Australia and Guam. 
This webworm attacks cabbage, cauliflower, collard, turnip, 
radish, mustard, horse-radish and beet and will feed on shep- 
herd's purse and purslane. It is sometimes destructive to 
plants in seed-beds. 

In the southern United States, the insect hibernates as a pupa 
in a compact cocoon of white silk attached to the injured plant 
near the base or situated just below the surface of the ground. 
The early seasonal history is very imperfectly known and the 
number of generations annually has not been definitely deter- 
mined. The moth has an expanse of about f inch ; the front 
wings are brownish yellow mottled with darker brown ; the 



INJURIOUS TO CABBAGE AND RELATED CROPS 17 

hind wings are pale fuscous. The female deposits her eggs 
singly or in small masses on the lea\'es of the plant. The egg 
is about sV inch in length, flattened and often provided with a 
distinct nipple-like projection at one end. When first laid it is 
light yellow or grayish but just before hatching takes on a 
pinkish browm color. Each female is capable of laying from 
300 to 350 eggs. In warm weather the eggs hatch in three or 
four days. 

The young caterpillars begin feeding on the underside of the 
leaves, eating off the epidermis in small irregular patches. The 
caterpillars often burrow into the leaf itself, into the leaf-stems 
and into the developing head. After the first molt, the cater- 
pillar usually covers its feeding grounds with a web of silk on 
which the excrement and other dirt collect. The caterpillars 
often attack the bud or heart of the plant, stop its growth and 
in many cases kill it outright. They sometimes eat out holes 
in the upper part of turnip roots. 

When full-grown, the caterpillar is about f inch in length, 
dull grayish yellow in color, and marked dorsally with five 
conspicuous brownish purple longitudinal stripes. On the 
sides and below there are similar but less distinct stripes. The 
caterpillars become full-grown in about eighteen days and after 
constructing their cocoons transform in a day or two to pupse. 
The pupa is about -^ inch in length and light yellowish brown in 
color. In the summer the insect spends about six days in the 
pupal state. There are probably three or four generations a 
year but the exact number has not been determined under 
field conditions. 

Control. 

In regions in which the cabbage webworm is likely to appear 
in injurious numbers, the plants should be protected by fre- 
quent applications of arsenicals beginning soon after trans- 
planting. In this way the young caterpillars will be killed 
c 



18 MANUAL OF VEGETABLE-GARDEN INSECTS 

before they are able to spin their proteetive webs. After the 
webs are spun, it is praetieally impDssibk' to reach them with a 
poison spray. Paris green, 1 pound in 50 gaUons of water, or 
arsenate of lead (paste) , 4 pounds in 50 gallons of water, will be 
found effective. In cases of severe infestation it would pay to 
collect and destroy the stumps and other refuse in the field 
after the crop is harvested and thus greatly reduce the number 
of hibernating pupse. 

References 

U. S. Div. Ent. Bull. 19. pp. 51-57. 1899. 
Ga. State Bd. Ent. Bull. 1, pp. 17-25. 1899. 
U. S. Div. Ent. Bull. 2.3, pp. 53-Gl. 1900. 
U. S. Bur. Ent. Bull. 109, pp. 23-45. 1912. 



The Garden Webworm 

Loxostege similalis Guenee 

Many kinds of vegetables are injured by a small dark yellow 
caterpillar feeding under the protection of a silken web. The 
insect is widely distributed throughout North and South 
America and the West Indies but is most injurious in the south- 
ern states and in the Mississippi Valley. The favorite food 
plants of the caterpillar are pigweed and careless weed 
{Amaranius hybridus) ; it also attacks a wide range of cultivated 
plants, including cabbage, cucumber, melon, squash, pumpkin, 
sweet potato, potato, tomato, eggplant, beet, bean, pea, 
lettuce, onion, corn, tobacco, flax, sugar-cane, clover, alfalfa 
and many grasses. 

How the insect passes the winter is not known, though 
judging from the habits of a closely allied species, Loxostege 
sticticalis, it probably hibernates as larvte in silken tubes in the 
ground. In Texas the first brood of moths is on the wing in 
early May ; in Illinois in late May and June. The moth has an 



INJURIOUS TO CABBAGE AND RELATED CROPS 19 

expanse of about f inch. The front wings are reddish buff 
marked with several transverse, interrupted Ughter Hues. The 
hind wings are hghter in coh)r with darker marginal and discal 
bands. The eggs are laid on the surface of leaves in bunches 
of eight to twenty. Hatching takes place in three or four days 
and the young larvpe at first feed on the under surface of the 
leaves, skeletonizing them, and spin a silken web inclosing their 
food. The larger caterpillars devour the entire leaves. They 
become mature in three or four weeks. The full-grown cater- 
pillar is nearly an inch in length, dull green above and greenish 
yellow below, marked on the dorsal surface with numerous 
shining black piliferous spots. The body is marked with a 
double pale median line and a whitish lateral line. Pupation 
takes place in a delicate silken cocoon spun among the debris 
at the base of its food plants. The pupa is brown in color. 
In the South there are probably as many as five generations 
while in Illinois Forbes records four broods annually. 

References 

Riley, Rept. U. S. Ent. for 1885, pp. 2().")-270. 
U. S. Bur. Ent. Bull. 57, pp. 11-14. 190G. 



The Purple-Backed Cabbage Worm 

Evergestis straminalis Hiibner 

Although this insect is common throughout the northeastern 
United States and Canada, it has been reported as injurious 
only in the maritime provinces. The insect also occurs in 
Europe. Its food plants include cabbage, turnip and horse- 
radish. When infesting the last, it is known as the horse- 
radish webworm. The caterpillars feed on the leaves, often 
webbing them together, and sometimes attack the crown boring 
into the stems and roots. The full-grown caterpillar is about 



20 MANUAL OF VEGETABLE-GARDEN INSECTS 

f inch in length, bristly, with the body tapering at both ends. 
The back is purplish brown to dark greenish black. There is a 
vellow stripe running through the spiracles and the underside 
of the body is dull greenish. The head is black, the cervical 
shield is black on the sides and the body is marked with numer- 
ous black tubercles. 

The larvae become full-grown in a little over a month and 
construct thin silken cocoons covered with dirt at or just below 
the surface of the ground. The larvae of the summer brood soon 
transform to pupae but those of the fall brood remain in the 
larval condition until the following spring. The pupa is about 
^ inch in length and brow^nish in color. The moth has an ex- 
panse of nearly an inch. The front wings are bright straw- 
yellow crossed with two fine brown lines and the veins are 
more or less lined with brown. On the outer margin of the 
wing there is a broad, brown shade inclosing a triangular straw- 
colored spot. The hind wings are straw-colored, translucent 
white at the base with brown marginal and submarginal lines, 
the latter usually incomplete and sometimes lacking. The 
moth deposits her eggs in small flat masses of three to more than 
a dozen, the eggs overlapping in the cluster. The egg is ovate 
and very flat when first laid but gradually swells with the 
development of the embryo. It is brownish yellow in color. 
The egg hatches in eight days. There are two and possibly 
three generations annually, the fall brood of caterpillars being 
the most injurious. 

Fortunately the purple-backed cabbage worm rarely becomes 
sufficiently abundant to require remedial treatment. Spray- 
ing with arsenate of lead (paste), 2 pounds in 50 gallons of 
water, should give satisfactory results. 

References 

Buckler, Ent. Mo. Mag. 19, pp. 126-130. 1882. 
Fletcher, Rept. Ent. Canada for 1904, pp. 231-232. 



INJURIOUS TO CABBAGE AND RELATED CROPS 21 



The Zebra Caterpillar 

Mamestra picta Harris 

In the northern United States and Canada east of the 100th 
meridian, a black, yellow-striped caterpillar is often seen in 
June and July and again in the fall feeding on the leaves of 
many garden plants. Its _ „____„ _— ^ 



mm^- 



Fi(i. 



17. — Full-grown zehru caterpillar 
(X i). 



striking colors often attract 
attention but the insect 
rarely becomes injurious 
except occasionally on cab- 
bage and celery. The full- 
grown caterpillar is about two inches in length, black, with 
bright yellow stripes on each side of the body (Fig. 17). 
The back between the yellow stripes is dotted with fine 
yellow spots and the space between the yellow bands on the 
side is crossed by fine slightly reticulated yellow lines. The 

head, legs and underside of 
the body are dark red. 

The caterpillars become 
mature in about a month 
and then enter the ground 
where in slight silken co- 
coons they transform to 
shining brown pupse about 
f inch in length. In the 
summer the pupal period 
is two or three weeks. The 
moth has an expanse of 1| to If inches. The front wings are 
purplish brown with a shade of light brown across the hind 
part of the wing. The round and reniform spots are gray. 
The hind wings are white edged with brown on the front and 
outer margins (Fig. 18). The moth deposits her globular, 




Fig. 18. 



Moth of the zebra caterpillar 

(X U). 



22 MANUAL OF VEGETABLE-GARDEN INSECTS 

sUfihtly flattened eggs in compact clusters of 125 to 150 or 
more on the underside of the leaves. The eggs hatch in a 
week or two and the young caterpillars feed for a time in 
colonies, skeletonizing the leaves, but later scatter and feed 
singly. They are at first nearly black but soon become pale 
or greenish and then develop the characteristic markings of 
the mature larva. There are two generations a year, the 
first brood of caterpillars being found in June and July and the 
second in the fall. The insect may hibernate either as partly 
grown caterpillars or in the pupal stage. 

The zebra caterpillar rarely becomes sufficiently abundant to 
require remedial measures on crops grown under commercial 
conditions. The young caterpillars may be killed by spraying 
with paris green or arsenate of lead. In the home garden 
hand-picking is the most satisfactory remedy. 

A closely related species, Mamestra legifima Grote, sometimes 
known as the striped garden caterpillar, has been reported as 
a general feeder on vegetable crops in the District of Columbia 
and in Georgia. The larva of this species differs from the zebra 
caterpillar in having the stigmatal yellow stripe broadly 
bordered with black above. In habits and life history, the 
two species are similar. 

The Cabbage Aphis 

Aphis brassiccE Linnaeus 

The cabbage aphis is supposed to be of European origin, 
but now occurs over practically the whole world wherever its 
food plants are cultivated. It attacks cabbage, cauliflower, 
brussels sprouts, kohlrabi, coUard, kale, brocolli, rape, turnip 
and radish. It also breeds to a considerable extent on a number 
of wild plants belonging to the mustard family. In the United 
States, especially in the northern and eastern states, it often 
takes first rank as an enemy of cabbage, cauliflower and related 



INJl'RIOUS TO CABBAGE AND RELATED CROPS 23 




Fig. 19. — Egg of 
tho cabbage aphis 
(X 19). 



plants. In some seasons the losses are severe, the crops over 

large areas being so badly infested that the growers plow them 

under early in the season. 

In that part of its range in which the winters are severe, 

the cabbage aphis hibernates exclusively in the egg stage; 

farther south many of the lice doubtless 

survive the winter. The elongate, oval, 

smooth, black, shiny eggs (Fig. 19), about 

■g^ inch in length, are found abundantly on 

the petioles and under surface of the leaves 

of cabbage plants left in the field over 

winter. Early in the spring the eggs hatch 

and the young lice find abundant food in 

the tender sprouts thrown out by the old 

cabbage stumps (Fig. 20). These lice of the 

first generation hatching from the eggs are all wingless females 

and are known as stem-mothers. As they increase in size, the 

lice molt four times, reaching 
maturity in about two weeks. 
A few days after the last molt 
they begin to give birth to living 
young. These stem-mothers 
may live for six weeks or more 
and give birth to forty or fifty 
young. The next generation of 
lice consists of wingless agamic 
females which resemble the 
stem-mothers very closely in 
form and color, being about 
j -^ inch in length, grayish green 

^ .„, c-^ .1 r 7i i" color and covered with a 

biLi. 20. — Stem-mothers of the i • • i 

cabbage aphis feeding on a whltlsh Waxy bloOIll (Fig. 21). 

sprout thrown out by an old Dm-Jug the remainder of the 

cal)hage stump (greatly eu- 

largcd). season reproduction continues 




24 



MANUAL OF VEGETABLE-GARDEN INSECTS 




vivip- 



Fifi. 21.— Win 

arous female of the 
cabbage aphis (X 8j). 



parthenogenetically, no eggs are produced and the young are 
born alive. From April first to October first, sixteen genera- 
tions have been known to develop. From 
time to time when the food supply be- 
comes limited, either from overcrowding 
or from some injury to the plant, winged 
forms (Fig. 22) are developed which fly 
to other plants and start new colonies. 

Cabbage plants often become infested 
in the seed-beds or very soon after 
transplanting. The lice soon become 
closely packed together in dense masses, 
often hiding the leaf from view. Their 
presence causes the leaves to curl, some- 
times forming deep pocket-like depressions, the inner surface 
of which is completely covered with lice. The aphids also 
cluster in the forming head. Badly infested plants cease to 
grow, the larger leaves die, the heads do not develop and in 
some cases the plant is killed outright. Figure 23 shows a 
badly infested radish seed-stalk. 

Late in the fall, true males and females are produced. The 
female is wingless and the male is winged. After pairing the 
female soon begins to deposit her eggs on the petioles and under 
surface of the cabbage 
leaves. When first laid, 
the eggs are pale greenish 
yellow in color but usually 
turn black in a few days. 




Fig. 22. — Winged viviparous female 
of the cabbage aphis (X 82). 



Control. 

Although cabbage lice 
are easily killed when hit 
by ordinary contact insecticides, it is difficult to control them 
economically under commercial conditions. The lice are pro- 



INJURIOUS TO CABBAGE AND RELATED CROPS 25 



tected in the curled leaves where it is difficult to hit them with 
a spray ; their bodies are covered with a white waxy bloom so 
that the spray does not readily wet them ; and they occur in 
dense masses or colonies, 
and considerable force is 
required in order to reach 
those beneath the others. 
Under commercial condi- 
tions, it is not possible to 
destroy all the lice by 
spraying. The best that 
can be expected is so to 
reduce their numbers that 
the plant will be able to 
continue its growth and 
develop the head. Efficient 
work can be done by spray- 
ing with the so-called 
whale-oil or fish-oil soap, 
10 pounds in 100 gallons 
of water, or with " Black 
Leaf 40" tobacco extract, 
f pint in 100 gallons of 
water with 4 or 5 pounds 
of soap added. The first 
application should be made 
as soon as the lice begin to 
cluster on the young plants. 
At least 100 gallons should 
be applied to each acre 
when the plants are young. The most effective and economical 
method of application is to use an ordinary potato sprayer 
(Fig. 24) equipped with a Y to which are attached two leads 
of hose 10 or 12 feet in length. At the end of each hose is an 




Fig. 2.3. — A radish seed-stalk infested 
by the cabbage aphis (enlarged). 



26 



MANUAL OF VEGETABLE-GARDEN INSECTS 



extension rod about 20 inches long, furnished with a Bordeaux 
or Vermorel nozzle, preferably the former. The pump should 
be able to maintain a pressure of at least 125 pounds. With 
this arrangement three men are needed, one to drive the horse 
and two to carry the nozzles. Attempts to use a potato 
spra>'er with fixed nozzles have been unsuccessful. A stiff 







Fiu. 24. 



Spraying for the cabbage aphis witli a traction potato-sprayer 
and two leads of hose. 



spray should be used, directed downward into the center of the 
plant. With sufficient force it will be driven into many of the 
curled leaves and will reach the lice. 

If the plants become infested with lice in the seed-beds, 
they should be dipped in a solution of whale-oil soap, 1 pound 
in 8 gallons of water, before transplanting. The roots should 
not be wet with the solution and the plants should not be left 
in the sun after dipping for fear of l)urning. 

Reference 
Cornell Agr. Exp. Sta. Bull. 300. 1911. 



INJURIOUS TO CABBAGE AND RELATED CROPS 27 

The TruNiP Aphis 
Aphis pseudohrdssica; Davis 

Although the tiinii}) aphis has undoubtedly been causing 
serious injury to cruciferous crops for many years, particularly 
in the South, it has been confused with other forms and its 
injuries attributed to other species. This aphid was not recog- 
nized as a distinct species until 1914 when it was described 
from specimens collected in New York and Indiana. It has 
received careful study in Texas where it is a serious pest of 
turnip, radish, cabbage and mustard, but is also found on kale, 
collard, rutabaga, rape and lettuce. It has been reported as 
feeding on bean but this attack w^as probably exceptional. The 
turnip aphis is most destructive in the fall, winter and early 
spring. Reproduction is rapid and the plants soon become 
covered with the lice, especially on the underside of the leaves 
anfl on the tender leaves at the center of the plant. Badly 
infested plants are stunted and many of them killed outright. 
The insect is distributed from Massachusetts to California 
southward to Louisiana and Texas and has been found in 
South Africa. 

So far males and egg-laying females (the so-called true sexes) 
of the turnip aphis have not been observed. In Texas the 
aphids pass the winter mostly on turnips. In that climate 
reproduction is considera})ly slower in the winter months but 
does not actually cease except for a few days at a time. Both 
wingless and winged forms occur at all seasons of the year but 
the relative abundance varies with the crowding of the plants 
and with their vitality. The wingless form when mature is a 
little over ^ig" hich in length, pale greenish, with the antennae 
pale, blackish towards the tip ; the legs are pale with the tips 
blackish. The body is slightly pulverulent, but much less so 
than in the cabbage aphis. The winged form is a little less 



28 MANUAL OF VEGETABLE-GARDEN INSECTS 

than Yt iii<^h "^ length, the head and thorax are black and the 
abdomen apple-green. The legs and antenna? are much darker 
than in the wingless form. Both forms give birth to living 
young. In the course of its development the aphis passes 
through four nymphal stages and becomes mature after the 
fourth molt. This requires from five to twenty-five days for 
the wingless forms and for the winged forms twelve to sixteen 
days, depending on the temperature. Rearing from the first 
born of each generation, thirty-five generations have been 
secured in one year in Texas. The number of young produced 
by each female varies considerably, from twenty-five to over 
one hundred, born over a period of eleven to twenty-seven 
days. During the summer in Texas, the turnip aphis is not 
found on cultivated plants, but its wild host plants have not 
yet been determined. In Indiana it is found abundantly on 
wild mustard and in Colorado on shepherd's purse. 

Control. 

The turnip aphis can be controlled by thorough spraying 
with "Black Leaf 40" tobacco extract, f pint in 100 gallons of 
water to which 4 or 5 pounds of soap have been added. This 
material will kill all the lice wet by the spray, the great difficulty 
being in hitting them. Spraying should begin early, when the 
first colonies of lice are found. Good pressure should be used 
and the spray applied with upturned angle nozzles, so directed 
as to wet the underside of the leaves. Effective work can 
also be done by spraying with whale-oil soap or laundry soap, 1 
pound in 7 gallons of w^ater. 

References 

Tex. Agr. Exp. Sta. Bull. 180. 1915. 
Ind. Agr. Exp. Sta. Bull. 185. 1916. 



INJURIOUS TO CABBAGE AND RELATED CROPS 29 



The Cabbage Root-^NIaggot 

Phorhia brassiccc Bouehe 

Throughout the greater part of the United States and Canada 
and in Europe, cabbage, cauhflower, turnip, radish and related 
crops are subject to serious injury by a small whitish maggot 
that burrows in the roots. It is also destructive in Alaska. 
In the northern states and Canada it is especially injurious to 
early cabbage and is 
very troublesome in the 
seed-beds of late cab- 
bage. Radishes also 
rarely escape attack. 
In some regions the 
growing of these crops 
has been abandoned 
temporarily because of 
the ravages of this pest. 

The parent flies, as a 
rule, emerge in early 
spring and have been 
recorded as feeding on 
the pollen of flowers. 
In the latitude of New 

York they emerge from the middle of JNIay till the middle of 
June and may be seen around the plants searching for a 
favorable place in which to deposit their eggs. In British 
Columbia eggs have been found as early as April 10. The fly 
is about 3- inch in length and resembles the house-fly in general 
appearance. The male (Fig. 25) is dark ash-gray in color with 
three blackish stripes on the thorax ; there is also a wide black 
stripe on the abdomen, which is continued laterally along the 
edge of the segments. The female is lighter in color and the 




Fig. 



Male fly of the cabbage root- 
maggot (X 5§). 



30 



MANUAL OF VEGETABLE-GARDEN INSECTS 



stripes are less distinct than in the male. This species is dis- 
tinguished from its near relatives by the presence, in the male 
fly, of a small tuft of bristles on the underside of the base of 
the hind femur (Fig. 26 ^4). As yet no one has discovered any 

characters by which the 
females can be distin- 
guished from those of the 
seed-corn maggot. The 
female deposits her small 
white eggs at the base of 
the plant, carefully tucking 
them down between the 
soil and the stem. Some- 
times the eggs are attached 
to the stem above ground. 
The egg is slightly over gV 
inch in length, elongate, 
bluntly rounded behind 
and pointed and flattened 
anteriorly, whitish in color, 
longitudinally striate and 
deeply grooved on one side. 
The eggs hatch in four to 
ten days depending on the 
weather. On hatching, the 
young maggot works its 
way along the main root, 
on which it feeds by rasp- 
ing out a channel in the 
surface. The maggots first 
attack the tender rootlets and then burrow into the main root 
where they may be found in slimy burrows just under the bark. 
They are sometimes seen in the stem above ground and even 
in the midrib of the leaves. Usually the first indication that 




Fig. 2G. — The femur and tibia of the hind 
leg of the male fly of: A, cabbage root- 
maggot ; B, onion maggot; C, seed-corn 
maggot. 



INJURIOUS TO CABBAGE AND RELATED CROPS 31 




Fig. 27. — Cabbage root-maggots at 
the base of an injured plant. 



a cabbage plant is seriously infested is a tendency to wilt l)a(lly 
in the heat of the day ; the leaves take on a blnish cast and then 
in a few days the plant 
droops and dies or it may 
survive in a sickly condi- 
tion for some time. When 
the maggots are present 
in great numbers, the root 
is riddled with their bur- 
rows, decay sets in and 
the death of the plant 
quickly ensues. In such 
cases great numbers of the 
maggots may be found in 
the soil surrounding the 
root, moistened by the 
juices of the injured plant (Fig. 27). The maggots become 
full-grown in about three weeks. They are then nearly | inch 

in length and shin- 
ing white in color. 
The body tapers 
toward the head, 
being largest be- 
hind, where it is 
obliquely truncate. 
The mouth-parts 
consist of a pair of 
strong black hooks 
curved downward, 
by which the insect 
is able to rasp off 
portions of the 
posterior end of the 
fleshy tubercles, of 




Fig. 28. — The cabbage root-maggot, side view 
( X 8) ; a, dorsal view of caudal segment, showing 
size, number and arrangement of fleshy tubercles, 
much enlarged ; b, outline of a cephalic spiracle, 
greatly enlarged. 



plant tissue. The truncate surface at the 
body is surrounded by a row of twelve 



mmm^' 



32 MANUAL OF VEGETABLE-GARDEN INSECTS 

which the middle hiwer pair are two-toothed. At the side of 
the body just back of the head is located a pair of spiracles 
which appear as brownish fan-like projections each having 
twelve divisions. These characters are used in separating the 
cabbage maggot from its near relatives (Fig. 28). 

When full-grown, the maggots work their way into the soil 
an inch or so, and there the skin contracts, hardens and turns 
brownish, thus forming the puparium (Fig. 29). Sometimes the 
maggots make this change in cavities in the roots. Within the 
puparium there takes place a remarkable series of changes 
whereby the tissues of the larva are broken down and rebuilt 
into the organs of the fly. The fly escapes from the puparium 
. through a circular seam at one end ; 

the length of the period passed in the 
puparium varies greatly; most of the 
flies emerge in twelve to eighteen days ; 
Fig. 29. — Puparium of a few may appear sooner, and a con- 
got {X7)^^ ^°ot-mag. siderable number emerge irregularly 
throughout the remainder of the season. 
A few puparia of this first brood may hold over till the 
following spring. A second brood of flies appears the last 
of June anfl throughout July. A third brood emerges from 
August till October. In some seasons a partial fourth brood 
may occur. As a rule it is the first brood of maggots that 
is most destructive to cabbage, cauliflower, radish and 
turnip, although occasionally the second brood causes seri- 
ous damage. The wuld plants in which breeding takes place 
are hedge mustard, white mustard and winter cress or yellow 
rocket, and probably other members of the mustard family, 
although shepherd's purse seems to be immune. In Canada the 
flies have been reared from maggots infesting the roots of bean 
and beet. In the North, as a rule, the insect hibernates in the 
puparium stage, but occasionally a few of the flies emerging late 
in the season may pass the winter under the protection of the 



INJURIOUS TO CABBAGE AND RELATED CROPS 33 

cabbage plants in the field. It is quite probable that farther 
south a greater number of the flies hibernate. 

Control. 

The means employed for the control of the cabbage maggot 
vary greatly with the character of the crop infested. 

For early cabbage and canliftower. — When infesting these 
crops, the injury may be in great measure prevented by the 
use of carbolic acid emulsion. For this purpose the stock 
emulsion is diluted with thirty parts of water. About half a 
teacupful of the emulsion sht)uld be poured around each plant 
a day or two after transplanting. The application should be 
repeated every week for a month. Apparently the carbolic 
acid emulsion does not to any great extent deter the flies from 
laying their eggs, but is effective in killing the eggs and recently 
hatched maggots with which it comes in contact. This method 
has been used to a considerable extent by commercial growers, 
but has not on the whole been found so satisfactory as the use 
of tarred paper cards. 

The value of the use of tarred paper cards to prevent maggot 
attack on early cabbage and cauliflower was demonstrated many 
years ago, but has not come into general use by commercial 
growers. This method of protection is more effective and at the 
same time less expensive than carbolic acid emulsion, and there 
is also no danger of injuring the plants. The cards are made of 
one-ply tarred felt roofing paper, and are cut in the form of a 
hexagon 4| inches in diameter. From one angle a slit extends 
to the center of the card and radiating from the center there are 
four to eight short slits whereby the card can be made to fit 
snugly around the stem of the plant (Fig. 30). The cards 
should be applied as soon as the plants are set out. To be most 
effective, the plants should be set on a ridge rather than in a 
depression because in the latter case the cards are likely to be- 
come covered with dirt. Thev cannot be used on short-stemmed 



34 



MANUAL OF VEGETABLE-GARDEN INSECTS 




>< 




Fig. 30. — Outline of tarred 
paper card ( X 3) . 



plants set sd deeply in the ground that the leaves are partly 
buried. After having been placed in position, the cards should 
be pressed down so as to rest smoothly 
on the soil and thus prevent the flies 
from working under them. 

The tarred pads can be obtained from 
seedsmen and dealers in garden sup- 
plies or the grower can make them 
himself by using the tool shown in 
Fig. 31. The method is described by 
Goff as follows : 

"The blade of the tool, which should 
be made by an expert blacksmith, is 
formed from a blade of steel, bent in 
the form of a half hexagon, and then taking an acute angle, 
reaches nearly to the center. The part making the star-shaped 
cut is formed from 
a separate piece 
of steel, so at- 
tached to the 
handle as to make 
a close joint with 
the blade. The 

latter is beveled from the outside all around, so that by remov- 
ing the part making the star-shaped cut, the edge may be 
ground on a grindstone. It is important that the angles in 
the blade be made perfect, and that 
its outline represents an exact half 
hexagon. 

"To use the tool, place the tarred 
■^ „., ,,. , paper on the end of a section of a log 

Fig. 32. — Diagram show- ' ^ . . ° 

ing how the tool is used, or piece of timber and nrst cut the 
The dotted line indicates j^^^^. ^^j j^^^^ notchcs. as indicated in 

the position of the edge ° 1 j> u 

of the tool. • Fig. 32, using only one angle ot the 




Fig. 31. — Tool for cutting the cards ( X j). 



INJURIOUS TO CABBAGE AND RELATED CROPS 35 

tool. Then commence at the left end, and place the blade as 
indicated by the dotted lines, and strike at the end of the 
handle with a light mallet, and a complete card is made. Con- 
tinue in this manner across the paper. The first cut of every 
alternate course will make an imperfect card, and the last cut 
in any course may be imperfect, but the other cuts will make 
perfect cards if the tool is correctly made, and properly used. 

"The cards should be placed about the plants at the time 
of transplanting. To place the card bend it slightly to open the 
slit, then slip it on to the center, the stem entering the slit, 
after which spread the card out flat, and press the points 
formed by the star-shaped cut snugly around the stem." 

For late cabbage seed-beds. — The depredations of the maggot 
in late cabbage seed-beds are often severe and necessitate the 
growers making much larger plantings of seed than would 
otherwise be required. Screening the beds with cheesecloth 
has been found an efficient and practicable method of protection 
and is now regularly practiced by cabbage growers in certain 
localities in New York. When this method is used, the seed 
should be drilled rather thickly in rows 6 to 8 inches apart. 
The corners of the bed should be staked out so that the cover 
can be applied before the plants come up. Boards, 6 to 10 
inches wide, are placed on edge around the bed making a tight 
enclosure and a cheesecloth cover is stretched over the top. 
The cloth is supported on galvanized wires stretched across the 
bed every 4 or 5 feet. The wires are sometimes supported at the 
middle by short stakes. The cloth is fastened to the boards by 
strips of lath. Care should be taken to have the boards fit 
tightly at the corners and at the ends, and the earth should be 
banked up around the bottom so that the flies cannot work their 
way under. E^'en the cheaper, loosely wo\en grades of cheese- 
cloth will exclude the flies, but as cloth ha\ing less than twenty 
threads to the inch is likely to stretch and pull apart so as to 
let in the flea-beetles, it is better to use cloth ha^'ing twentv 



36 MANUAL OF VEGETABLE-GARDEN INSECTS 

to thirty threads to the inch. Cloth that is too tightly woven 
will exclude too much sunlight and make the plants spindling. 
The screen should be removed a week or ten days before trans- 
planting in order to harden the plants. Plants grown under 
cheesecloth cover are not only protected from the attacks of 
root-maggots and flea-beetles but, owing to the retention of 
warmth and moisture, make a much better growth than in the 
open. Screened beds do not have to be as large as open beds 
because under these conditions practically all the plants make 
the proper growth. 

For radishes. — Carbolic acid emulsion has been used with 
some success on this crop, but better results can be obtained by 
growing the plants in beds screened with cheesecloth as de- 
scribed above. 

References 

Cornell Agr. Exp. Sta. Bull. 78. 1894. 
N. J. Agr. Exp. Sta. Bull. 200. 1907. 

N. Y. (Geneva) Agr. Exp. Sta. Bull. 301. 1908. 

N. Y. (Geneva) Agr. Exp. Sta. Bull. 334. 1911. 

N. Y. (Geneva) Agr. Exp. Sta. Bull. 382. 1914. 

N. Y. (Geneva) Agr. Exp. Sta. Bull. 419. 191(). 
Dept. Agr. Canada Ent. Bull. 12, pp. 9-29. 1916. 

N. Y. (Geneva) Agr. Exp. Sta. Bull. 442. 1917. 

The Seed-Corn ^Maggot 

Phorhin fusciceps Zetterstedt 

The injury caused by the cabbage root-maggot is often 
augmented by the presence of a closely related species which 
has received the rather inappropriate common name given above. 
The seed-corn maggot is generally distributed throughout the 
United States and Canada and also occurs in Europe. In addi- 
tion to cabbage and related plants, it attacks sprouting seed corn, 
beans and peas, and has been recorded as feeding on seed pota- 
toes and onions. The food of this species is not confined to vege- 



INJURIOUS TO CABBAGE AND RELATED CROPS 37 

table matter, for at the time (if tlie great outbreak of migratory 
locusts in the West, the maggots attacked the eggs of these 
grasshoppers which then occurreci in great abundance. Gen- 
erally, however, the maggots feed on planted seeds which have 
softened in germination or from decay. They are sometimes 
very destructive to seed beans especially in cold, wet, backward 
seasons. In some cases more than half of the crop is destroyed 
over large areas in this way. The maggots burrow into the 
seed-leaves, destroying them, and then mine into the stem. 
Some of the injured beans fail to germinate; more often, 
however, the seed-leaves pushup through the soil, but as the bud 
is injured the plants fail to leaf out. 

The flies of the seed-corn maggot closely resemble those 
of the cabbage root-maggot, but the males may be distinguished 
by lacking the tuft of hairs on the under side of the base of the 
hind femur, and by having on the under side of the hind tibia 
a row of short spines (Fig. 2() C). The females of the two 
species are indistinguishable. As far as known, the life histories 
of the two species are very similar. 

Control. 

The seed-corn maggot, when attacking cabbage and related 
crops, may be controlled by the means suggested for the cabbage 
root-maggot. The injury to germinating beans may be pre- 
vented in large measure by planting the seed shallow in cold 
wet seasons. Beans planted in this way come up more quickly 
and, being in a vigorous condition, are able to outgrow any slight 
injury to the seed-leaves. 

The Western Radish ]\Iaggot 

Phorbia planipalpis Stein 

On the Pacific Coast the cabbage root-maggot is replaced by a 
closely related species with similar habits. The maggots of this 



38 MANUAL OF VEGETABLE-GARDEN INSECTS 

fly liave been found iiifestiiiji- radish, cabbaj2;e, cauliflower, ruta- 
baga and turnip and have also been observed abundantly in the 
pods of lupine and field peas, destroying the seeds. The fly 
closely resembles the adult of the cabbage root-maggot. The 
male is ^ inch in length and the female about ^ inch. 

The insect hibernates both as adults and as puparia. The 
female deposits her white, elongate, slightly curved eggs, about 
P6 inch in length, singly or in loose masses on the roots or 
on the leaves near the crown. On hatching, the maggots bur- 
row into the radish roots rendering them unfit for food. ]\Iany 
maggots often infest the same root and sometimes kill the 
plant. The full-grown maggot is :j to f inch in length and is 
whitish or yellowish in color. The body tapers toward the head 
and is truncate behind. When mature the maggots transform 
to puparia either within the root or in the surrounding soil. 
The pupariura is about ^ inch in length and brownish in color. 
There are said to be several generations annually. 

A satisfactory method of control does not seem to have been 
worked out. 

Reference 
Essig, Insects of California (Ed. 2), pp. 3.3G-.339. 1915. 

The Harlequin Cabbage Bug 

Murgantia histrionica Hahn 

In the last half century the harlequin cabbage bug has spread 
from its home in Central America and Mexico northward to 
Nevada, Colorado, the southern part of Illinois, Indiana, Ohio, 
Pennsylvania and New Jersey and to Long Island, New York. 
It also occurs in California. Except in the extreme northern 
part of its range, it is a most destructive enemy of cabbage and 
related plants. It is also known as the terrapin-bug, fire-bug 
and calico-back. When food is abundant, it usually confines 
its attacks to plants belonging to the mustard family, being es- 



INJURIOUS TO CABBAGE AND RELATED CROPS 39 



pecially fond of horse-radish, but when its favorite food plants 
have been destroyed the bugs will migrate to adjoining fields 
and feed on almost any plant available. Eggplant, asparagus, 
potato, tomato, okra, bean, beet and even nursery stock are 
sometimes severely injured under such circumstances. The in- 
sect also breeds on a large number of wild plants belonging to 
the mustard and caper families. 

The harlecjuin bug hibernates as an adult under rubbish ; in 
southern Florida the insect remains on the food plants during the 
winter, but its ac- 
tivities are more ^ 
or less retarded. 

As soon as spring '-:'., 

opens, the adults 
emerge from win- 
ter quarters and 
congregate on any 
cole plants avail- 
able. The female 
deposits her eggs 
on the underside 
of the leaf in 
masses each con- 
taining normally 
twelve eggs ar- 
ranged in two 
rows of six each. 

The females that have wintered over are more prolific than those 
of later generations ; they are each capable of laying about one 
hundred eggs. Females of the next generation lay on an aver- 
age only about seventy-five eggs. The egg is oV inch in length 
by 3V inch in width, cylindrical, truncate at each end ; the 
upi)er end is provided with a circular lid which is pushed ofi' at 
the time of hatching. The egg is pearl-gray or pale yellow, 




Fig. 33. 



— Egg-clusters of the harlequin cabbage buf: 
on the underside of a leaf ( X 2) . 



40 



MANUAL OF VEGETABLE-GARDEN INSECTS 




Fig. 34. — Eggs of 
the harlequin cab- 
bage bug, side view 
(X5). 



with two black bands, one broader and more distinct near the 

top and the other near the bottom. There is a black spot just 

above the lower band and sometimes the eggs are irregularly 

blotched with black. The cap of the egg has a semicircular 
black mark inside the marginal ridge. The 
egg has a striking resemblance to a small 
white keg with black hoops, the spot on the 
side suggesting thebunghole (Figs. 33 and 34). 
The eggs hatch in four to eleven days, de- 
pending on the temperature. The newly 
hatched nymph is pale green in color with 
black markings. The insect passes through 

five nymphal stages and acquires wings at the fifth molt. In 

its later stages, the nymph is brightly colored — black, orange 

or yellow, and red. About two months after hatching, the 

nymphs reach maturity and transform to adults. The adult 

(Fig. 35) is about f inch in length, mottled red, black and 

yellow or orange. In all stages the 

bugs have a disagreeable odor and 

are distasteful to birds. 

In feeding, both adults and 

nymphs puncture the plants and 

suck out the juices. A half dozen 

bugs are enough to kill a cabbage 

or turnip plant. The severity of the 

injury inflicted seems to be out of 

proportion to the amount of food 

wit|idrawn from the plant and is 

supposed to be produced by a poison 

which the insect injects while feeding. 

Injured cabbage plants wither and turn brown as if scalded. 

The crop in whole fields is often com})letely destroyed. Many 

gardeners have been deterred from planting cabbage and collards 

because of the ravages of this pest. 




Fig. 35. — The harlequin cub- 
bage bug, adult ( X 3|). 



INJURIOUS TO CABBAGE AND RELATED CROPS 41 

Control. 

Both the nymphs and adults of the harlequin cabbage bug 
are very resistant to contact insecticides. In fact it is prac- 
tically impossible to kill them in this way without injuring the 
plants. Loss may be prevented in large measure by practicing 
clean cultural methods of farming. After the crop has been 
harvested, all cabbage stumps and other refuse should be plowed 
under or destroyed in some other way. Hibernating shelter in 
the form of overgrown fence rows or patches of rank weeds 
should be reduced to a minimum. It is sometimes advised to 
leave a few piles of rubbish in the field in the fall as traps for the 
hibernating bugs. After they have collected in such shelter, 
the rubbish should be burned. 

Very effective work can be carried on against the bugs in the 
spring by the use of trap crops. Kale, mustard and rape are 
often utilized for this purpose. If a few of these plants are sown 
so as to be available for food before the crop it is desired to protect 
is up, the insects will congregate on these plants where they may 
be killed by spraying with pure kerosene or in some other way. 
In the fall it is a good plan to leave a few cabbage, turnip or kale 
plants after the remainder of the field has been cleaned. The 
bugs will collect on these plants where they may be easily de- 
stroyed before going into hibernation. The destruction of the 
adults early in the spring is the most important measure for the 
control of the insect ; if this work is done with thoroughness the 
crop will remain relatively free from attack for the remainder of 
the season. If the bugs are not destroyed in early spring, the 
only recourse is to hand-pick them into pans of kerosene — a 
tedious and laborious operation. 

References 

N. r. Dept. Agr. Eiit. Circ. 8. 1904. 

U. S. Bur. Ent. Circ. 103. 1908. 

Smith, .Jour. Ec. Ent. 2, pp. 108-114. 1909. 



42 



MANUAL OF VEGETABLE-GARDEN INSECTS 



The Green Soldier-Bug 



Acrosternum hilaris Say 

In the northern states the fruit of peach, apple and pear 
is occasionally seriously injured by the punctures of a large 
green stink-bug. The insect is widely distributed throughout 
the United States and Canada and southward to the West Indies 
and Brazil. It has also been recorded as attacking cabbage, 
bean, pea, corn, okra, tomato, eggplant, turnip and mustard, 
and it also feeds on a large number of 
shrubs and trees. The insect has been 
carefully studied as a fruit pest in Ohio. 
The green soldier-bug (Fig. 36) is from 
^ to f inch in length, oblong, oval, 
bright green in color with the edges of 
the head, thorax and abdomen narrowly 
bordered with yellowish or reddish. 
The winter is passed by the adults 
hidden away in dry sheltered places, 
often under fallen leaves. The bugs 
emerge about the middle of May and 
egg-laying begins about the first of 
June continuing until the middle of July. The eggs are 
about iV ii^ch in length, oval, largest toward the top which is 
provided with a small circular cap, surrounded by a single row 
of about sixty-five club-shaped spine-like processes. The eggs 
are usually light yellow in color but are sometimes light green. 
Just before hatching, they become pinkish or reddish. They are 
attached to the leaf by one end and arranged in clusters of 
twenty to fifty. Each female usually lays two batches of eggs 
and a few may lay a third. The first batch is usually the 
largest and the last very small. The eggs hatch in about a week 
and the young nymphs remain in a c()nii)act cluster near the egg- 




FiG. 36. — The green 
soldier-bug (X If). 



INJURIOUS TO CABBAGE AND RELATED CROPS 43 

shells till after the first molt. They are about xV inch in length, 
with the head and thorax brownish blaek and the abdomen marked 
with transverse black and light blue bands. In the course of its 
development the insect passes through five nymphal stages and 
acquires wings at the fifth molt. In the fifth stage the nymph 
is nearly ^ inch in length, with the head and thorax l)lackish 
marked with orange-yellow ; the abdomen is yellowish green. 
The nymphs require from seven to ten weeks to reach maturity 
and adults of the new brood begin to appear the last of July, 
but some of the nymphs do not reach maturity until the first of 
October. There is only one generation annually. 

A closely related species, Nezara vinduJa Linnseus, is some- 
times injurious to cabbage in the southern states. The plants 
are injured in much the same way as by the harlequin cab- 
bage bug. The adults so closely resemble those of A. hilar is 
that they are distinguished with difficulty. The most striking 
difference is that in the former there is a distinct, small black 
spot on the hind outer corner of the exposed part of each ab- 
dominal segment. In the latter these spots are very small and 
inconspicuous. The insect ranges from Virginia to Texas and 
northward to Indiana. It has also been reported as injuring 
tomato, sweet potato, okra, pepper, cotton and orange. 

No satisfactory method for the control of the green soldier- 
bugs, other than hand-picking, has been suggested. 

Reference 
Ohio Agr. Exp. Sta. Bull. .310. 1917. 

The Cabbage Leaf-Miners 

There are three species of flies, the maggots of which develop 
within the leaves of cruciferous plants, producing large whitish 
blotched mines. 



44 



MANUAL OF VEGETABLE-GARDEN INSECTS 



The imported tin nip Icaj'-vdner, Seapton/.ipa Jlaveola Meigen 

Originally a native of Europe where it is known as the turnip 
leaf-miner, this insect was introduced into the United States 
some time before 1891, and is now widely distributed, ranging 

from Alaska to New Hampshire 
and south to Kentucky and 
Virginia. 

Very little is known concerning 
its early seasonal history and 
the number of broods occurring 
annually has not been deter- 
mined. The parent fly ap- 
parently deposits her eggs on 
the upper surface of the leaves. 
On hatching, the young maggot 
burrows into the leaf and feeds 
just below" the upper epidermis, 
producing at first an irregular 
tortuous burrow w'hich is sud- 
denly widened to form a large 
blotch. The epidermis over the 
mine turns whitish and by a 
coalescence of several mines the 
A young^ cabbage leaf wholc leaf ma}' take ou this 
color (Fig. 37). The full-grown 
maggot is about ^ inch in length, 
whitish in color and cylindrical in form, tapering towards the 
head and bluntly truncate behind. When mature the larval 
skin hardens and turns reddish brown to form the puparium 
within which the true pupa is to be found. This trans- 
formation may take place in the mines but usually the puparia 
are found under rubbish on the surface of the ground. In 
Kentuckv the flies have been observed to emerge in late 




Fig. 37 

showing the work of the imported 
turnip leaf-miner 



INJURIOUS TO CABBAGE AND RELATED CROPS 45 

fall. The insect may, therefore, hibernate in the adult condi- 
tion. The fiy has an expanse of about j^ inch and its general 
color is brown, the antennae being yellow and the legs pale. 
This species has been recorded as feeding on cabbage, cauli- 
flower, radish, turnij), Iceland poppy, horse nettle and mouse- 
ear. 

The native cabbage leaf-miner, Scaptoniyza aduHa Locw 

This species is closely related to the preceding and has been 
reared in company with it. It injures the plant in a similar way. 
It is widely distributed from ]\Iaine to Florida and west to 
Illinois but is more abundant in the southern part of its range. 

The imported cabbage Icaf-Diiner, Scaptoinyza 
graviinuDi Fallen 

This European leaf-miner is now distributed in this country 
from New Hampshire to Texas. Its habits are similar to those 
of the two preceding species. In this country it has been reared 
from cabbage and in Europe it attacks several plants including 
chickweed, lamb's quarters, cockle and catchfly. 

There seems to be considerable doubt as to the determination 
of the three species just treated. Sturtevant, who has carefully 
studied these flies, does not believe that S. flacenla has been in- 
troduced into this country and is of the opinion that the studies 
on which the above account is based were made on a mixture of 
S. adusta and S. graminum. 

Control. 

Little is known as to the best measures for controlling these 
leaf-miners. Their injuries are rarely serious. It might be 
possible to kill the maggots in the mines by spraying with a 
strong mixture of nicotine sulfate and soap. 



46 



MANUAL OF VEGETABLE-GARbEN INSECTS 



References 

Ky. Agr. Exp. Sta. Bull. 40, pp. 46-51. 1892. 
Coquillett, Insect Life, 7, pp. 381-383. 1895. 
U. S. Div. Ent. Bull. 33, pp. 75-77. 1902. 



The serpentine leaf -miner, Agromyza pusilla Meigen 

The leaves of cabbage, turnip, radish and rape are sometimes 
disfigured by narrow, tortuous mines caused by a small, trans- 
lucent yellow maggot about ^ inch in length. This insect has 

also been found mining 
the leaves of potato, 
spinach, beet, water- 
melon, and pepper, as 
well as many wild and 
f,)rage plants. When 
mature, the maggots 
transform within the leaf 
into brownish puparia 
about ^ inch in length. 
In the summer about 
ten days are spent in 
this stage. The fly 
(Fig. 38) is from ^ to 
Yj inch in length, shining black and marked with yellow in a 
most variable way. The flies deposit their small, white, oval 
eggs, about yws inch in diameter, in the tissue of the leaf 
on the underside. The eggs hatch in three to eight days. 
The time required for each generation varies from twenty- 
three to forty days depending on the temperature. Breeding 
is continuous throughout the growing period and the number 
of generations depends on the length of the season. 

Reference 
Webster and Parks, Jour. Agr. Research, 1, pp. 59-87, 1913. 




Fig. 38. — The &y of the serpentine leaf- 
miner (X 20). 



INJURIOUS TO CABBAGE AND RELATED CROPS 47 



The Falsi-; Chinch-Bug 



Nijsuis ericce Schilling 

Cabbage, cauliflower, radish and turnip are occasionally sub- 
ject to injury by a small grayish brown bug known as the 
false chinch-bug. This insect is widely distributed through- 
out the United States from California to New Hampshire and 
southward. It has been reported as most troublesome in the 
upper Mississippi Valley and in the western 
states. These bugs are very general 
feeders and sometimes injure beets, let- 
tuce, mustard, potatoes, corn, strawberry, 
cotton and even apple nursery stock and 
young grape vines. Seed-beets during the 
second year's growth are sometimes 
severely injured. 

The false chinch-bug hibernates as an 
adult in rubbish and under the leaves 
around the base of its food plants. The 
adult (Fig. 39) is about \ inch in length, 
grayish brown in color, sprinkled with 
blackish ; the head is marked with two 
longitudinal black lines and there is a transverse black band 
across the front of the prothorax ; the legs are yellowish brown. 
The bugs are most destructi^T in early spring when the adults 
come out of hibernation in great numbers and swarm on the 
young plants. In feeding, they puncture the leaves and suck 
out the sap, causing the plants to wilt, turn brown and die. 
The early spring and late fall broods deposit their eggs in 
cracks of the soil. The other broods place their eggs in the 
heads of various wild plants. The egg is described as beijig 
slender, cylindrical, irregularly wrinkled and tapering at both 
ends; it is vellow in color, orange-red at the anterior end. 




Fk;. 39. — The false 
chinch-bug, adult 
(X 11). 



48 MANUAL OF VEGETABLE-GARDEN INSECTS 

The younfi; nymplis are yellowish markerl with indistinct 
loniijitiulinal dark lines. They feed almost exclnsively on 
weeds such as pepper-grass, shepherd's purse, Russian thistle 
and sage brush. The older nymphs are more distinctly 
marked with brown and reddish lines. When mature, the 
bugs scatter to all kinds of vegetation but in cases of drought 
are forced to congregate on cultivated plants. In Illinois the 
first brood nymphs mature in the latter part of May and the 
second in July. The broods overlap so that in midsummer 
all stages may be found together. In Kansas there are said 
to be at least five generations annually. 

In Colorado there is a smaller race of the species which bears 
the name Nysius mimdus Uhler. It has been recorded as very 
injurious to beets grown for seed. 

Control. 

Much can be done to prevent injury by the false chinch-bug 
by clearing the fields of all rubbish in the fall, thus depriving 
the bugs of hibernating shelter. This may be accomplished 
by burning over the fields. If the vegetation is not sufficient 
to carry the fire, straw may be scattered over the field. A 
gasoline torch may be used to kill the insects where they have 
congregated on weeds or clumps of grass. The insects may 
also be killed by thorough spraying with "Black Leaf 40" 
tobacco extract, 1 pint in 100 gallons of water to which 10 
pounds of soap have been added. Burlap shields made sticky 
with a coat of crude petroleum are sometimes used to capture 
the bugs on plants that cannot be sprayed. 

References 

Riley, .5th Rept. Ins. Mo., pp. 111-114. 1873. 
Osborn, Rept. U. S. Ent. for 1887, p. 162. 
Forbes, 23rd Rept. 111. State Ent., pp. 117-118. 1905. 
U. S. Farm. Bull. 762. 1916. 



INJURIOUS TO CABBAGE AND RELATED CROPS 49 
The Cabbage Curculio 

Ceutorliynchiis rapcv Gyllenhal 

One of the minor pests of cabbage, cauliflower, kale, radish 
and horse-radish is a small ash-gray weevil about ^ inch in 
length. This beetle is a native of Europe where it has never 
attracted attention as an enemy of cultivated crops. It was 
apparently introduced into America in New England about 
the middle of the last century but is now generally distributed 
throughout the northern states from New York to Virginia 
westward to Nebraska and Colorado. It also occurs in Cali- 
fornia. 

The insect hibernates in the adult condition and the weevils 
appear in the field in early spring. They feed slightly on the 
leaves and also puncture the stems of their food plants, eating 
out a cavity as deep as they can reach with the beak. The 
female deposits her eggs singly in similar punctures in the 
stems. The tissue surrounding the egg-puncture becomes en- 
larged, forming a noticeable scar. The egg is about -^ inch 
in length, o\'al and shining white. The eggs hatch in about a 
week and the grubs, several of which may infest a single stem, 
hollow out the contents, often causing the plants to turn 
sickly and die. The full-grown grub is ^ to j inch in length, 
milky white with a brownish head. The larvse become mature 
in about three weeks, gnaw their way out of the stem and 
enter the ground wdiere at a depth of less than an inch they 
transform to milky white pupae in oval earthen cells. The 
beetles appear in about a week, or during the early part of 
June in the District of Columbia, and feed for a time on the 
stems and leaves of their food plants. Although the new brood 
of beetles appears at this early date, there is apparently only 
one generation annually. 

Larvae of the cabbage curculio have been found in the stem 
and crown of cabbage and cauliflower, the petioles of horse- 



50 MANUAL OF VEGETABLE-GARDEN INSECTS 

radish and probably also infest the radish. Serious injury to 
cabbage and cauliflower plants in tlie hot-bed has been re- 
ported from Missouri. The beetles, however, prefer to deposit 
their eggs in the stems of wild pepper-grass, hedge mustard and 
shepherd's purse. When these plants are available for egg- 
laying, cultivated crops are not usually infested. In case wild 
plants are allowed to grow as a trap crop, they should be de- 
stroyed before the larvae reach maturity else they will merely 
serve to increase the abundance of the pest. 

Reference 
U. S. Div. Eiit. Bull. 23, pp. 39-50. fOOO. 

The Cabbage Seed-Stalk Weevil 

Ceutorhynchus quadridens Panzer 

Another European weevil closely related to the one last 
treated has been introduced into Massachusetts and Long 
Island, New York. On Long Island this weevil has proved a 
serious pest to cabbage grown for seed, hundreds of larvae 
being found in a single stalk, their presence causing the plants 
to wait and break over just before the seed begins to mature. 
Whole fields are often ruined in this way. The adult is slightly 
smaller than the cabbage curculio and the scales with which 
the body is covered are white intermixed with gray hairs. This 
weevil also infests kale and turnip and in Europe it is recorded 
as breeding in mustard, water cress, horse-radish and rape. 

No satisfactory method .of controlling this insect is known. 

The Red Turnip Beetle 

Entomoscelis adonidis Pallas 

In western Canada cabbages, radishes, turnips and beans 
occasionally have the leaves eaten by the larva? and adults of 



INJURIOUS TO CABBAGE AND RELATED CROPS 51 

a scarlet beetle about \ inch in length, marked with three black 
stripes down its back and with a black patch on the prothorax. 
The insect is native to the region, where it fed originally on 
wild cruciferous plants, particularly the prairie wall-flower, 
but it is also found in Europe and Asia. The beetles deposit 
their red to dark brown, elongate-elliptical eggs, ^ to ^ inch 
in length, in large loose masses under clods of earth. The 
mature larva is black above and yellowish beneath, slug- 
shaped and about § inch in length. The larvae are said to feed 
mostly at night. When full-grown they burrow into the soil 
for an inch or so and there transform to bright orange pupjie 
about \ inch in length. The winter is passed in the egg stage 
in the ground. The beetles become noticeable in the fields in 
July and August and may be found as late as November. 

In Austria the winter eggs hatch in the early spring and the 
larvtne become full-grown in the latter part of April. The 
beetles appear in May and after feeding a few days go into 
aestivation in the ground where they remain till September or 
October. It is quite probable that when the habits of this 
beetle are thoroughly studied in America, its life history will 
be found to be much the same as in Europe. 

Spraying with arsenate of lead (paste), 2 or 3 pounds in 50 
gallons of water, will kill many of the beetles and their larvae. 

Reference 
Fletdicr, Ropt. Ent. Canada for 1S92, pp. 10-13. 

Other Insects Injurious to Cabbage and Related Crops 

Corn ear-worm : 211 ' 

Southern corn root-worm : 222 

Western corn root-worm : 225 

Carrot beetle : 18.5 

Tarnished plant-bug : 192 

Sugar-beet webworm : 97 

Southern beet webworm : 101 



52 MANUAL OF VEGETABLE-GARDEN INSECTS 

Spinach aphis : 105 

Western twelve-spotted cucumber beetle: 114 

Belted cucumber beetle : 115 

Garden springtail : 139 

Potato aphis : 150 

Common stalk-borer : 157 

Bean thrips : 69 

Garden flea-hopper : 77 

Bean leaf -roller : 81 

Onion thrips : 245 

Argus tortoise beetle : 238 

Spotted cutworm : 262 

Well-marked cutworm : 263 

Greasy cutworm : 265 

Red-backed cutworm : 267 

Dark-sided cutworm : 268 

Striped cutworm : 270 

Dingy cutworm : 271 

Shagreened cutworm : 272 

Granulated cutworm : 273 

Clay-backed cutworm : 274 

Variegated cutworm : 276 

White cutworm : 278 

Glassy cutworm : 279 

Yellow-headed cutworm : 281 

Spotted-legged cutworm : 282 

Speckled cutworm : 283 

Clover cutworm : 284 

Bristly cutworm : 285 

Army cutworm : 287 

Fall army-worm : 292 

Yellow-striped army-worm : 295 

Striped blister-beetle : 302 

Margined blister-beetle : 305 

Ash-gray blister-beetle : 306 

Black blister-beetle : 307 

Spotted blister-beetle : 309 

Immaculate blister-beetle : 310 

Segmented black blister-beetle: 310 

Potato flea-beetle : 314 

Pale-striped flea-beetle : 321 

Smartweed flea-beetle : 323 

Striped cabbage flea-beetle : 324 

Phyllotreta ramosa: 326 

Four-spotted cabbage flea-beetle : 326 



INJURIOUS TO CABBAGE AND RELATED CROPS 53 

Hemiglyptus bnsnlis : 326 
Sinuate-striped flea-beetle : 326 
Western eal)bage flea-beetle : 327 
Horse-radish flea-beetle : 328 
Hop flea-beetle : 335 
Root-knot nematode : 338 
Millipedes: 342 
Wheat wireworm : 348 
Slugs: 354 
Salt-marsh caterpillar : 359 



CHAPTER III 

PEA AND BEAN INSECTS 

The more important insect enemies of the pea are of Euro- 
pean origin, while those of the bean are native. The seed 
weevils are, on the whole, the most troublesome pests of these 
crops, especially in the South. Peas are subject to widespread 
and destructive outbreaks of the pea aphis, especially where 
they are grown in large areas for the cannery. The seed-corn 
maggot occasionally causes serious damage to seed beans in 
seasons when the weather is cold and wet at planting time, and 
under similar weather conditions snails occasionally prove 
very destructive to the foliage. 

The Pea Weevil 

Bruchus pisorum Linnaeus 

The pea weevil is a native of the Old World but was intro- 
duced into America more than one hundred and seventy years 
ago. Peter Kalm records having found it in Pennsylvania, 
New Jersey and southern New York in 1748 and states that 
because of its ravages the settlers had in large measure been 
forced to discontinue the growing of peas. The insect is now 
widely distributed in most parts of the world where peas are 
grown. The economic importance of this pest is indicated by 
the statement of James Fletcher in 1903 that in Ontario alone 
the annual loss amounts to more than a million dollars. In 
this province many of the farmers had given up the growing 

54 



PEA AND BEAN INSECTS 55 

of peas iK'cause of the depredations of this pest. A simiUir 
condition obtains in many parts of Germany. The pea ^vee^•il 
is less abundant in the northern part of its range and a large 
])roiiortion of the seed peas planted in the South are obtained 
from the northern states, Canada and northern Europe. 

The pea weevil (Fig. 40) is considerably larger than the 
other species infesting the pea and the bean. It is about i 
inch in length, brownish in color mottled with gray, white and 
dark brown. There is a white spot on the 
middle of the hind margin of the prothorax 
and the wing-covers are crossed by a more 
or less indistinct whitish band towards the 
tip. The wing-covers do not extend to the 
tip of the abdomen and the exi)osed part 
is white with t\\'o large l)lack spots at 
the tip. When viewed from above, the 
])roth{)rax has the appearance of being Fio. 40. — Tho pea 
slightly- notched on the sides. The base of ^^«^" (^ ^')- 
the antennse and the front and middle tlbioe and tarsi are 
reddish brown. There is a sharp tooth on the underside of 
the hind femur toward the tip. 

The wee\ils appear in the field about the time the peas are 
in blossom and after feeding slightly on the foliage, the female 
deposits her elongate, fusiform, yellow eggs singly on the sur- 
face of the newly formed pods. The egg is attached by a 
^'iscid substance that on drying becomes white and glistening. 
As many as fifteen to twenty eggs may be laid on a single pod. 
The eggs hatch in about twelve days and the young larva 
bores into the pod. In case it does not happen to enter the 
pod directly over a young pea, it may burrow through the 
tissue of the pod as a miner until it reaches one of the seeds. 
The hole through which the young larva enters soon heals over 
and is indicated merely by a small brownish dot. The newly 
hatched larva is yellow with a black head. The prothorax is 




56 MANUAL OF VEGETABLE-GARDEN INSECTS 

armed with a series of six strong spines and a pair of prominent 
toothed plates which point backward. These structures are 
apparently of use to the larva in making its way through the 
pod and in entering the pea. It also possesses three pairs of 
small slender legs. Soon after entering the pea, the grub 
molts and the spiny structures on the prothorax are lost. The 
larva becomes proportionately shorter and thicker and lies 
normally in a curved position. It soon works its way to the 
center of the pea and there eats out a large cavity. When 
full-grown, it is about j inch in length, white in color, with 
brownish mouth-parts. The short stumpy legs are easily 
overlooked. In Italy the larva reaches maturity about forty 
days after hatching. It then cuts out a smooth round hole to 
the surface of the pea, leaving only the outer hull as a cover- 
ing. It lines the cavity with a paste-like substance, thus ex- 
cluding all excrement from its pupal chamber. The pupa is 
dirty wdiite in color. The insect remains in this stage from 
nine to seventeen days. Only one weevil is found in a pea. 
In the warmer parts of its range, many of the beetles emerge 
from the seeds soon after transformation but in the North a 
large proportion remain in the seeds until the following spring 
and are often planted with the seed peas. Weevils that emerge 
in the field hibernate in dry sheltered places and fly back to the 
pea fields the following spring. There is only one generation 
annually. 

In the case of small peas, the weevil destroys about one half 
of the contents, in larger peas about one third. Infested peas 
are not suitable for planting. Experiments in Kansas have 
shown that in a germination test only about 25 per cent of the 
infested peas w411 sprout. In a field experiment in which thir- 
teen varieties of peas were used, only 4.4 per cent came up 
and only 3.8 per cent produced fair sized plants. At the same 
time, 64 per cent of uninfested peas of the same varieties gave 
a good stand of strong plants. Experiments in Canada have 



PEA AND BEAN INSECTS ' 57 

shown that in the case of small peas, infested seed produced 
only 13 to 20 per cent of plants which bore pods and in the 
case of large peas 16 to 28 per cent. 

References 

Costa, Insetti, etc., pp. 133-140. 1857. 

Rilev, 3rd Kept. Ins. Mo., pp. 44-50. 1871. 

Kan. Agr. Exp. Sta. Bull. 19, pp. 193-196. 1890. 

Chittenden, U. S. Dept. Agr. Yearbook for 1898, pp. 234-239. 

Fabre, Souvenirs Entomologiques, 8, pp. 23-47. 

Frank, Arb. Biol. Abt. Land. Forst. Wirths. Kais. Gesundheitsamte, 

1, pp. 86-114. 1900. 
Fletcher, U. S. Div. Ent. Bull. 40, pp. 69-74. 1903. 



The Beax Weevil 

Bruchus obiectus Say 

Probably the bean weevil is a native of the Xew World. It 
was first described in 1831 from specimens collected in Loui- 
siana. It first attracted attention by its injuries in 1860 in 
Rhode Island. The insect is now widely distributed throughout 
southern Canada, the United States, Mexico, Central America, 
the West Indies and South America. It also occurs in the 
Mediterranean region, Persia, Indo-China, jVIadeira, the Azores 
and the Canaries. Its favorite food plant is the common 
kidney bean, Phaseolus vulgaris, but limas and cowpeas are 
sometimes attacked in the field, and in storage it will also 
attack the faba bean, peas, chick peas, lentils and the seeds of 
Lathyrus sativus. The bean weevil is a very serious pest in the 
South. It is not so destructive in the northern states and 
Canada and it is from this region that a large proportion of the 
seed beans are obtained. 

The bean weevil (Fig. 41) varies considerably in. size but 
averages about | inch in length. The general color is light 
brownish. The wing-covers are mottled with light brown, 



58 MANUAL OF V EGET ABLE-GARDEN INSECTS 




Fig. 41. — The l^eaii 
weevil ( X 9) . 



dark brown, gray and black, arranged in narrow longitudinal 
stripes. On the middle of each wing-cover near the inner 
margin is a fairly distinct light gray longitudinal bar. The 
exposed tip of the abdomen, the base and last segment of the 
antenna^ and the legs, except the hind femora below, are dull 
reddish brown. The hind femur is armed 
on the underside near the tip with one large 
and two small teeth. The beetles appear 
in the field about the time the beans are in 
blossom and feed slightly on the surface of 
the leaves. In cool weather the beetles are 
sluggish, but in bright warm days they can 
take wing quickly and fly to a considerable 
distance. As soon as the pods become 
nearly full-grown but while they are still 
green, the females begin egg-laying. The female first gnaws a 
slit through the pod close to the ventral suture and by means 
of her extensile ovipositor then deposits a cluster of eggs on the 
inside of the pod. The hole made by the beetle in the pod does 
not heal over but persists as a discolored spot even in the 
dried pod. The egg (Fig. 42) is translucent 
white, elongate-ovate, and about -^ inch in 
length ; the surface is slightly roughened. The 
eggs are sometimes inserted through an opening 
in the pod where it has been injured or where it 
has split in drying. The time required for the 
hatching of the eggs varies considerably with the 
temperature but apparently has not been ac- 
curately determined for eggs laid in fresh pods. 
On hatching, the young larva bears little resemblance to the 
mature grub. It is white, the head yellow, the mouth-parts 
brown and the eyes black. Three pairs of distinct, slender 
functional legs are present and the body is clothed with long 
hairs which serve to keep the larva upright when crawling. 




Fig. 42. — Egg 
of the bean 
weevil (X 40). 



PEA AND BEAN INSECTS 59 

The young larva crawls actively ahoiit until it finds a bean which 
it enters through a small round hole about y¥s inch in diameter. 
In about three days after hatching, the larva molts and assumes 
the general appearance of the mature grub. The legs, eyes 
and the long hairs on the abdomen are lost, the body becomes 
proportionately shorter and thicker and the grub assumes a 
curved position. The larva burrows diagonally into the bean 
a short distance and there eats out a large cell covered in part 
only by the thin semi-transparent outer coat of the bean. It 
then lines the cell with a yellowish white paste, thus excluding 
all excrement from the pupal chamber. The length of the 
larval stage varies greatly with the 
temperature, or from eleven to forty- 
two days. The full-grown larva is ^ 
to Y inch in length. The insect trans- 
forms to a white pupa within the cell 
and remains in this stage from five to 
eighteen days. Soon after transforma- 
tion, the beetle neatlv cuts out a Fig. 43. — Beans showing 

circular lid through the seed-coat of ^^'viR '' "''''^' ^"^ '^^ 
the bean and makes its escape (Fig. 

43). The entire life cycle requires from twenty-one to eighty 
days. The beetles emerging in the field soon begin laying eggs 
for another generation. The number of generations that occur 
in the field depends on the temperature and the length of the 
season. Breeding is continuous in stored beans provided the 
temperature is sufficiently high. In the vicinity of Washing- 
ton, D. C, there are probably six generations annually. The 
number of weevils reared from a single bean depends on the 
size of the seed. In cases in which the beetles are allowed to 
breed in stored seed undisturbed, they often reduce the contents 
to a powdery mass held together by the hull. As many as 
twenty-eight weevils have been reared from a single bean. 
Weevily beans are unfit for planting. In a large proportion of 




60 



MANUAL OF VEGETABLE-GARDEN INSECTS 



such beans, the germ is destroyed and many of the others are 
so injured that they cannot produce healthy plants. 

References 

Riley, 3rd Rept. Ins. Mo., pp. 52-56. 1871. 

Lintner, 7th Rept. N. Y. State Ent., pp. 255-279. 1891. 

Fabre, Souvenirs Entomologiques, 8, pp. 48-65. 

Kan. Agr. Exp. Sta. Rept. 1889, pp. 206-210. 

Slingerland, Psyche, 6, pp. 445-447. 1893. 

Chittenden, U. S. Dept. Agr. Yearbook for 1898, pp. 239-242. 



The Broad Bean Weevil 

Bruchus rufimanus Boheman 

The broad bean weevil is similar to the pea weevil both in 
the form and general appearance of the beetle and in its life 
history. It is a troublesome pest in Europe, northern Africa, 
Syria and Persia and has been recently introduced into 
California. By preference it attacks the European broad 
bean or horse bean but will also breed in 
peas and certain species of vetch. In Cali- 
fornia the weevils appear in the field by 
the last of March. The beetle closely re- 
sembles the pea weevil, both in form and 
markings. The latter are, however, more 
diffuse and the black spots at the tip of 
the abdomen are indistinct or lacking alto- 
gether (Fig. 44). The tooth on the under- 
side of the hind femur is more obtuse than 
in the pea weevil. The female deposits 
her eggs on the outside of the bean pods, as many as 
thirty-four having been found on a single pod. The eggs 
are attached by a mass of sticky material. The egg is 
elongate-ovate, white to greenish yellow, smooth, a little over 
^ inch in length and about one half as wide. The eggs hatch 
in twelve to fifteen days. The larvae leave the egg-shell through 




Fig. 44. — The broad 
bean weevil ( X 9) . 



PEA AND BEAN INSECTS 61 

the side attached to the pod and soon find their way into the 
young beans. The point of entrance is indicated in the dried 
beans by a small black dot. The larva very closely resembles 
that of the pea weevil. It eats out a cell in the bean, its posi- 
tion being indicated by a transparent spot where the larva has 
eaten out the contents under the outer hull. In California the 
larvae begin to pupate about the first of August and transform 
to adults the same season. Hibernation usually takes place in 
the beans but if they are kept in a warm room, many of the 
weevils will emerge in storage. From one to five larvae may be 
found in a single bean. There is only one generation annually 
and the weevils do not breed in dried beans. Infested beans 
are lighter in weight and their value as food for stock is con- 
siderably lessened. Furthermore, the percentage of germina- 
tion even of beans containing only one larva is considerably 
less than that of uninfested seed, and of beans that have been 
injured by four or five larvae, only about one third will germinate. 

References 

Costa, Insetti, He (Ed. 2), pp. 269-273. 1877. 
Lintner, 7th Rept. N. Y. State Ent., pp. 279-285. 1891. 
U. S. Bur. Ent. Bull. 96, pp. 59-82. 1912. 

The Four-Spotted Bean Weevil 

Bruchus quadrimaculatus Fabricius 

This weevil breeds by preference in the seeds of the cowpea 
but in storage will also attack peas and beans. The species is 
distributed throughout southern Europe, Africa, the East 
Indies, South America, the West Indies, Central America, 
Mexico and the southern states. The four-spotted bean weevil 
(Fig. 45) is about | inch in length ; the head and thorax are 
black ; on the middle of the hind margin of the prothorax are 
two small spots of whitish pubescence. The markings of the 
wing-covers vary greatly but in typical specimens are brownish. 



62 MANUAL OF VEGETABLE-GARDEN INJECTS 

black at the base and on each there is a large dark spot at the 
middle of the outer margin and another at the tip. The ex- 
posed tip of the abdomen is brownish, usually marked with 
two black spots. The antennse are black, reddish brown at 
the base. The legs are brownish except the basal two thirds 
of the hind femora which is black. 

Under cage conditions, the beetles have been observed to 
deposit their eggs singly on bean pods. The egg is oval, 
lemon-yellow and about -^ inch long by 
^ inch wide. It is attached to the pod 
by a thin sheet of gelatinous substance 
which extends beyond the egg. Under cage 
conditions in New York, it required fifty 
days fqr the eggs to hatch. When breed- 
ing in dry beans, the eggs are glued to the 
surface of the seed and hatch in thirteen 
Fig. 45 — The four- ^^ twenty days. On hatching, the young 
spotted bean weevil larva borcs directly through the pod 
and attacks the seeds within, or when 
the eggs are attached to the seed, it enters directly under 
the egg-shell. The young larva closely resembles that 
of the pea weevil but differs in the armature of the pro- 
thorax. The full-groAvn larva is very similar to that of the 
bean weevil from which it may be distinguished by the larger 
area of black on the head just above the clypeus. The larva 
also injures beans in much the same way as the bean weevil. 
Pupation occurs within the seed. The rate of development 
varies considerably with the temperature and moisture. Several 
larvjie may infest the same seed and successive generations may 
be produced until the food supply is exhausted. 

References 

Slingerland, Psyche, 6, pp. 447-449. 189.3. 

Chittenden, U. S. Dept. Agr. Yearbook for 1898, pp. 245-248. 




PEA AND BEAN INSECTS 



63 



The Cowi'EA Weeml 



Bruchus chinensis Linnaeus 

Beans and peas in the southern states often become infested 
by the cowpca wee\'il. This insect is widely distributed through- 
out the tropics. In the United States its range extends nortli- 
ward to INIaryland and Iowa. The 
beetle (Fig. 46) is from -^^ to \ inch 
in length, brownish in color and may 
be distinguished from the other 
species in this country by the two 
ivory-white spots on the middle of 
the hind margin of the prothorax. 
The wing-covers are brownish, dark 
at the base and usually crossed 
with a darker band at the middle. 
In the male the antennae are pec- 
tinate. 

The female glues her eggs on the outside of the pods. The 
egg is ovate, flattened on the side of attachment, translucent, 
about -yV inch in length by -7^^ in width. The eggs hatch in 
four to ten days and the young larva bores through the pod 
and enters the seed. In the field, the larvae become full-grown 
in two or three weeks in midsummer. They closely resemble 
those of the bean weevil and several larvae may infest a single 
seed. Pupation takes place within the seed and transforma- 
tion to the beetle occurs in four or five days in warm weather. 
Breeding continues in stored seeds and six or seven broods 
may develop annually in the District of Columbia. 




Fig. 4G. — The rowpea 
weevil ( X 8) . 



References 

U. S. Div. Ent. Bull. S, pp. 24-27. 1897. 
U. S. Bur. Ent. Bull. 9G, pp. 83-94. 1912. 



64 MANUAL OF VEGETABLE-GARDEN INSECTS 

The Control of Pea and Bean Weevils 

Seed infested by living weevils should never be used for 
planting, for it is in this way that many of the weevils gain 
access to the field. Neither is it good economy to use infested 
seed for planting in which the weevils have been killed, because 
the percentage of germination of such seed is low and the 
plants produced are weak and unproductive. In the case of 
the pea weevil and the broad bean weevil, species that do not 
breed in dried seed, the insects may be killed by holding over 
the seed until the second year before planting. The weevils 
will emerge in storage and, being unable to escape, will die 
without laying eggs. In the case of the bean weevil, the four- 
spotted weevil and the cowpea weevil, in which breeding con- 
tinues in the dried seeds, holding over the seed w^ould be use- 
less. Fumigation with carbon bisulfid is the most efficient and 
practicable method of killing the weevils in stored seed. To be 
most effective, the treatment should be made in the fall soon 
after harvesting. The seed is placed in a tight barrel or box 
to which a cover has been fitted as nearly air-tight as possible. 
Carbon bisulfid is used at the rate of ^ to 1 ounce to a bushel. 
In larger quantities in specially constructed fumigating cham- 
bers, the weevils can be killed by using carbon bisulfid at the 
rate of 3 pounds to 100 cubic feet. The liquid should be placed 
in some shallow dish like a pie tin on top of the seed. The 
fumigating box should then be covered tightly and fumigation 
should be allowed to continue for twenty-four to thirty-six hours. 
More satisfactory results will be obtained if the temperature 
is kept at 70 degrees F. or above. In fumigating, care should 
be taken not to smoke or to bring fire of any kind in contact 
with the gas, as the carbon bisulfid vapor is very inflammable. 

When there is only a small quantity of seed to be treated 
and when it is impracticable to fumigate, the weevils may be 
killed by suspending the seed in a bag in a kettle of cold water 



PEA AND BEAN INSECTS 65 

and then heatinji; the water to a tenijierature of 140 deiirees F. 
The seed should then be si)i'ead out where it will dry quickly. 

The Bean Leaf-Beetle 

Cerotoma trifurcata Forster 

The bean leaf-beetle is a native American insect distributed 
from New York, southern Canada, ^Minnesota, ^Missouri and 
Kansas southward to Florida, Texas and New Mexico. It 
also occurs in Porto Rico. Its native food plants are the hog 
peanut, bush cloxer and tick trefoil. It has been reported as 
injurious to the bean, cowpea, pea, soybean, cultivated beggar- 
weed and corn. 

The insect hibernates in the adult stage and in the South 
the beetles appear in the field in April, in the District of Colum- 
bia the middle of jNIay, and in the more northern part of their 
range not until the last of June or the first of July. The 
beetle (Fig. 47) is about -j inch in length, yellowish to reddish 
in color ; the head is black and each wing-cover has a black 
band running around its base and extending backward close 
to, but separated from, the margin nearly to the tip. Near 
the inner margin is a row of three black spots, larger in front 
and smaller behind. The antennae are yellowish toward the 
base and darker toward the tip. The legs are marked with 
black and yellow, the hind pair being the darkest. The beetles 
usually rest on the underside of the leaves where they are 
easily overlooked. In feeding, they eat out holes in the leaves 
and when abundant leave only the larger veins. The plants 
are often defoliated and the crop is ruined. The beetles do 
not take wing readily but when disturbed fall to the ground. 
The female deposits her eggs in clusters in the soil at the base 
of the plants. Clusters of over forty have been observed but 
the average is about twelve. The egg is about -^ inch in 
length, elliptical in outline, orange in color and the surface is 



G6 



MANUAL OF VEGETABLE-GARDEN INSECTS 



sculptured with rows of hexagonal pits. One female has been 
known to deposit 795 eggs, but this is undoubtedly far above 
the average. The female continues to lay eggs for nearly a 

month. The eggs hatch in about 
eighteen days in the spring and in 
the summer in five to eight days. 
The larvae feed on the roots, the stem 
underground, and are particularly 
fond of the bacterial nodules found 
on the roots of leguminous plants. 
The full-grown lar\'a is -^ inch in 
length, white in color, with the head, 
cervical and anal shields dark. The 
larva becomes mature in three weeks 
in summer to six or more in the fall, 
transforms to a white delicate pupa 
in a small earthen cell in the ground 
and in about a week the transforma- 
tion to the adult takes place. In the North there is only 
generation a year. In 
south probably three. 




Fig. 47. — The bean Icri- 
beetle (X 3i). 



one 



Virginia there are two, and farther 



Control. 

The beetles may be killed by spraying the vines with arse-* 
nate of lead (paste), 4 pounds in 100 gallons of water, taking 
care to apply the spray to the underside of the leaves. The 
application should be made at the first appearance of the 
beetles before they have had time seriously to injure the plants 
and in order to destroy the females before they have laid their 
eggs. In the home garden, the beetles may be collected by hand 
but spraying is the more convenient and practical treatment. 



References 

Chittenden, U. S. Div. Ent. Bull. 9, pp. G4-71. 1897. 
McConnell, Jour. Ec. Ent., 8, pp. 261-266. 1915. 



PEA AND BEAN INSECTS 67 

The Grape Colaspis 

Colas pis brunnea Fabricius 

This insect occasionally riddles the foliage of beans with 
holes, its work being similar to that of the bean leaf-beetle. The 
foliage of beet, cantaloupe and potato is sometimes eaten. 
The beetle is about ys i'^ch in length, uniform yellowish brown 
with the wing-covers distinctly striate. The larvae are found 
on the roots of strawberry, corn, timothy and other grasses. 
They are white, with the head and cervical shield yellowish 
and |- to 1^ inch in length. They reach maturity in May or 
June and pupate in earthen cells. The beetles are common 
■ throughout the summer but are most abundant in June and 
July. The insect is generally distributed throughout the 
northern states and Canada east of the Rocky Mountains. 

In case the beetles become sufficiently abimdant to threaten 
serious injury, they may be poisoned by spraying the plants 
with arsenate of lead (paste), 2 or 3 pounds in 50 gallons of 
water. 

References 

Forbes, 1.3th Rcpt. Rtcatc Ent. 111., pp. 1.56-159. 1884. 
Forbes, 22ncl Rept. State Ent. 111., pp. 145-149. 1903. 

The Bean Ladybird 

Epilachna corrupfn Mulsant 

In the foot-hills from Wyoming through Colorado to Arizona, 
New Mexico, Texas and ^lexico, bean plants are sometimes 
seriously injured by one of the ladybird beetles. The insect 
also occurs in western Kansas. 

The bean ladybird passes the winter in the adult condition. 
In New Mexico the beetles appear in the field from early June 
to the middle of July. The beetle (Fig. 48) is about -j inch in 



68 



MANUAL OF VEGETABLE-GARDEN INSECTS 



length, o\al in outline, strongly convex and pale yellowish to 
brownish orange in color. The eyes are black and each wing- 
cover is marked with eight small black spots arranged in three 
transverse rows. The beetles feed on the foliage, eating out 
holes in the leaves, and deposit their elongate, yellowish eggs 
in clusters of forty or more on the underside of the leaves. 
Each female lays on the average nearly 300 eggs and one beetle 
was observed to lay over 750. The egg is about -^ inch in 
length, oval and yellow in color. The eggs hatch in four to 
nine days and the young larvae begin feeding on the underside 
of the leaves, skeletonizing them. The 
larva passes through four stages in the 
course of its development and becomes 
full-grown in two or three weeks. It is 
then about f inch in length, light yellow 
in color and clothed with stout branched 
spines. When mature it attaches the tip 
of its body to the leaf and transforms 
into a yellow pupa about -g- inch in 
length. The pupal period occupies from 
three to five days. The entire life cycle 
is completed in three to four weeks in New Mexico. In 
Colorado there is said to be but one generation annually ; in 
New Mexico there are two. 

The seasonal history of the bean ladybird has been studied 
most carefully in New Mexico. In that region the over- 
wintered beetles lay eggs from the middle of June to the first 
of August. The larvse of the first brood are found until the 
latter part of August, producing a brood of beetles some of 
which may hibernate. The earliest beetles to mature of the 
second brood begin laying eggs about the middle of Jul\' and 
continue till the end of the season. The two generations thus 
overlap during July and August and it is at this time that the 
larvse and beetles are most abundant and destructive. In 




Fig. 48. — The bean 
ladybird (X 3). 



PEA AND BEAN INSECTS 69 

many cases the plants are completely defoliated and the entire 
crop is ruined. The beetles also have the habit of eating into 
and destroying the green pods. 

Control. 

The bean ladybird may be controlled by spraying the plants 
with arsenate of lead (paste), 2 to 4 pounds in 50 gallons of 
water. In localities in which the beetle is annually destruc- 
tive, much injury may be avoided by planting early so that 
the crop will mature early enough to escape serious injury, 
(lean farming to eliminate hibernating shelter for the beetles 
and a proper rotation of crops will accomplish much to prevent 
loss. In the home garden, hand-picking the beetles and eggs 
may be practiced to advantage and the larvse may be brushed 
oflF on the hot ground during the heat of the day where they 
will perish without regaining the plant. 

References 

Col. Agr. Exp. Sta. Bull. 19, pp. 25-27. 1892. 
N. M. AgT- Kxp- f>ta. Bull. lOG. 1917. 

The Beax Thrips 

Heliothrips fasciatus Pergande 

In California beans are subject to serious injury by a species 
of thrips, the mature female of which is about -^ inch in length, 
with the head and body black. The narrow front wings are 
black, white at the base and with a white band towards the 
tip. The antennje are black and white and the wings are 
fringed with long white hairs. The male is somewhat smaller. 
Both young and adult thrips are found working on the leaves, 
stem and pods of the bean, which they injure by piercing the 
tissues with their sharp mouth-parts and then suck out the 
juices at the point of injury. The injured leaves turn yellowish 



70 MANUAL OF VEGETABLE-GARDEN INSECTS 

or white, dry up and die. In some cases the plants may be 
entirely killed. The bean thrips has been most injiu-ious in 
California but also occurs in Idaho, Utah, Nevada, Arizona and 
Tennessee. It is not confined to the bean but attacks many 
other plants, including beet, cabbage, lettuce, radish, potato, 
tomato, pea, pear, alfalfa and cotton. Among weeds, its 
favorite food plants are spiny lettuce, sow thistle and wild 
heliotrope. 

The bean thrips hibernates in the adult condition on the 
underside of the leaves of nasturtium, beet, wild heliotrope 
and many other plants. It is also found in dried leaves 
and under rubbish. In the warmer parts of its range, the insect 
is active throughout the greater part of the year, feeding being 
interrupted only for a short time during cool spells. On emerg- 
ing from hibernation, the adults immediately seek their food 
plants and after feeding for a short time the female deposits 
her minute translucent white, bean-shaped eggs, about ywu 
inch in length in the tissue of the leaves, in the veins and even 
in the stems of beans. The eggs hatch in thirteen to eighteen 
days. The newly hatched nymph is about -g-^ inch in length 
and uniform translucent white in color with the eyes reddish. 
In the second stage, the nymph is about ^ inch in length 
with the head and prothorax light yellow and w^ith the re- 
mainder of the body translucent white and stained on the side 
with crimson. During the first two stages, the nymphs feed 
on the leaves in the same way as the adults. When full-grown, 
they desert the plants and hide in rubbish and in cracks in the 
ground and there molt. In the third stage, the nymph or so- 
called prepupa is slightly smaller than in the preceding stage 
and the wing-pads are well developed. The insect does not 
feed in this stage but in from one to six days, depending on the 
season, it molts again. In the fourth stage or so-called pupa, 
the nymph is ^ inch in length, yellow or orange in color, 
marked with crimson on the sides and across the abdomen and 



PEA AND BEAN INSECTS 71 

the antennpe are carried back over the head. In this stage the 
insect is shiggish and takes no food. In four to fourteen days, 
dependino; on the season, the nymph transforms to the adult. 
In California there are seven generations a year, the first and 
last being small. In the early part of the season the thrips 
are most abundant on their wild food plants. They do not 
become abundant on beans until later in the season, although 
a few may be found on this crop from the time it first comes up. 

Control. 

The injury caused by the bean thrips may be lessened by 
clean cultivation to destroy the weeds on which the insect 
breeds. Early planting and thorough cultivation will tend to 
produce a rapid and healthy growth and render the plants 
more able to withstand injury. In the garden the thrips may 
be controlled by spraying with "Black Leaf 40" tobacco ex- 
tract, 1 part in 800 parts of water in which enough soap has 
been dissolved to produce a good suds. 

Reference 
U. S. Bur. Ent. Bull. 118. 1912. 

The Pea Aphis 

Macrosiphum pisi Kaltenbach 

Without doubt the most serious insect enemy of the pea is 
this large green plant-louse. The insect was undoubtedly intro- 
duced into this country from Europe. Although there is evi- 
dence that it was present here as early as 1878, it did not attract 
attention as a pest until 1899 when there was an extensive and 
highly destructive outbreak in the Atlantic states, most serious 
in \'irginia, INIaryland, Delaware and New Jersey. The losses 
occasioned by this insect in the Atlantic states during the years 
1899 and 1900 have been estimated at .$7,000,000. While the 
pea aphis has not maintained this rate of destructiveness in 



72 MANUAL OF VEGETABLE-GARDEN INSECTS 

recent years, it is still the most serious insect pest with which 
pea-growers have to contend. In England the pea aphis has 
been known as a pest since the early part of the nineteenth cen- 
tury. It received the scientific name under which it is now 
known in Germany in 1843, although it is quite probable that 
it had been more or less imperfectly described previously. 

The pea aphis occurs generally throughout Europe and has 
been introduced into British India and South Africa. In 
North America it is widely distributed throughout the United 
States and Canada, being most abundant in the East, but has 
been reported from Colorado, Texas, New Mexico, Arizona 
and the states on the Pacific Coast. In addition to the pea 
the insect attacks red clover, crimson clover, white clover, 
alsike, vetch, sweet pea, sweet clover, bush clover, alfalfa and 
lentil. It als:) occasionally infests shepherd's purse. In 
Europe the aphis has been recorded as feeding on several 
other leguminous plants. 

The pea aphis usually passes the winter on clover and breed- 
ing is resumed on this plant in the spring. At this time the 
aphis shows a decided preference for crimst)n clover on which it 
multiplies rapidly. In Virginia about the last of April or the 
first of May, winged aphids are produced that migrate to peas. 
These migrating forms are all females that reproduce by giving 
birth to living young without being fertilized. These winged 
viviparous females (Fig. 49) are i to ^ inch in length, pea-green 
in color, with the tip of the cornicles, tip of the tibife, and the 
tarsi black. The eyes are red. The antennfc are slightly 
longer than the body. The winged forms settle on the pea 
plants, usually on the stem, and begin to give birth to living 
young. In the course of its development, the young aphis 
passes through four immature stages, molting four times, and 
at the last molt becoming adult. On the average it requires 
about ten days for the young aphis to reach maturity, and when 
about twelve days old it begins to produce living young. Re- 



PEA AND BEAN INSECTS 



73 




Fig. 4n. — Winged vivii)ar()U,s female 
of the pea aphis ( X 5). 



production continues for an average peri(^d of eighteen days 
at the rate of one to eleven a day. The number of yoinig 
produced by a single female averages eighty. Both wmged 
and wingless forms are pro- 
duced, the relative proportion 
of the two varying with the 
seastm and with the crowded 
condition of the plant. The 
wingless form (Fig. 50) re- 
sembles the winged vi\'iparoiis 
female in color. The stems 
become covered with the lice, 
and the leaves, blossoms and 
pods are soon attacked. In- 
fested leaves become slightly 
thickened and curled, infested blossoms arc blasted and injured 
pods are stunted, deformed and rendered worthless. Badly in- 
fested plants take on a sickly yellowish appearance and may be 
killed outright. Sometimes whole fields are destroyed in this 
way. In such cases, the ground has a whitish 
appearance from the cast skins of the plant 
lice. ^Yheneve^ the plants become crowded, 
winged forms are produced that migrate to 
other parts of the field or to other food plants. 
In Virginia it has been found that while 
breeding is more or less continuous throughout 
the year on clover, the insect migrates more or 
less regularly between its other food plants. 
Fig. 50. — Wingless Peas are infested from April to the first of July 

viviparou-s female , p,, i.i- -j-xuu 

pea aphis (X 5). '^^'^i^'ii many oi the plant-lice migrate to bush 

clover, sweet clover, alfalfa and the clovers. 

Peas again })ecome infested in August and the plant-lice remain 

here until the advent of cold weather when they return to clover. 

Counting from the first-born of each brood, twenty or twenty- 




74 MANUAL OF VEGETABLE-GARDEN INSECTS 

two generations of the pea aphis may develop annually in Vir- 
ginia. In Indiana breeding experiments have shown that 
counting from the last-born, thirteen generations are produced 
annually. The insect hibernates on clover either as mature 
viviparous females, winged or wingless, or in the cooler part of 
its range in the egg stage. Males and egg-laying females are 
produced late in the fall only. The male is usually winged, is 
considerably smaller than the viviparous female and has darker 
markings on the head, thorax and abdomen. Only a few 
wingless males have been observed. The egg-laying female is 
wingless, and much smaller than the wingless viviparous form 
which it resembles closely in color. The hind tibiae are con- 
siderably thickened basally and bear numerous sensoria. The 
winter eggs are usually found on red or crimson clover. The 
egg is about -is inch in length, elliptical oval in outline and 
pale when first laid, changing to jet black. 

The pea aphis is subject to the attacks of several parasitic and 
predaceous insects and particularly to a fungous disea'se that often 
destroys a large proportion of the lice. These natural enemies 
are most effective during the warmer part of the season and 
often nearly exterminate the lice locally on certain food plants. 

Means of control. 

As the pea aphis lives over winter and begins breeding in 
the spring on clover, especially on crimson clover, the presence 
of these crops in the near vicinity of fields of early peas is a 
menace to the latter. In such cases, when crimson clover is 
being grown for green-manure arid is seen to be infested, it 
should be plowed under before the migration of the lice to peas 
takes place, without waiting for it to reach its full growth. 
The ground should then be harrowed and rolled. In cases in 
which the clover is grown for hay, it might be well to sacrifice 
this crop in order to save the peas. Experience has shown that 
peas grown in rows about thirty inches apart are, as a rule. 



PEA AND BEAN INSECTS 75 

less seriously infested than when they are sown broadcast or 
in narrow drills. When the peas are grown in rows, the lice 
can be controlled by spraying with "Black Leaf 40" tobacco 
extract, 10 ounces in 50 gallons of water to which 4 pounds of 
whale-oil soap have been added. A traction sprayer is used, 
fitted with nine nozzles and arranged to spray three rows at 
a time. One nozzle is directed downward and the other two 
nozzles throw the, spray slightly upward into the row. The 
pump should be able to give a pressure of 120 to 150 pounds 
when all nine nozzles are in operation. With this outfit it is 
possible to. work effectively on twelve acres of peas a day. In 
spraying for the pea aphis, it is important to begin early, soon 
after the winged forms from the clover appear in the field. If 
the work is started on time, it is usually possible to control 
the pest with two or three applications at intervals of about a 
week. In Maryland, Delaware and New Jersey, it was found that 
much loss could be avoided by raising the main crop of peas for 
the cannery early in the season before the aphis became abundant. 
At the time of the first serious outbreak of the pea aphis in 
this country, spraying machinery and insecticides were not as 
effective as those now on the market and spraying experiments 
at that time gave very unsatisfactory results. Methods were, 
therefore, devised for destroying the lice by mechanical means. 
The aphids were brushed from the plants to the ground during 
the heat of the day with pine boughs and a cultivator was 
immediately run between the rows. In this way many of the 
lice were either killed by the heat or buried in the soil. This 
method is now little practiced under commercial conditions 
but might be followed to advantage in the home garden. 

References 

Del. Agr. Exp. Sta. 12th Rept., pp. 169-186. 1900. 

Va. Truck Exp. Sta. Bull. 13. 1914. 

U. S. Dept. Agr. Bull. 276. 191.5. 

Smith, loth Rept. State Ent. Va., pp. 32-6.3. 1914-1915. 



76 



MANUAL OF VEGETABLE-GARDEN INSECTS 




Fig. 51. — Winged viviparous female 
bean aphis (enlarged). 



The Bean Aphis 

Aphis rumicis Liunseus 

This black plant-louse is widely distributed throughout the 
o'reater part of the subtropical aiul temperate regions of the 

world. Its summer food 
plants include a great 
variety of vegetable 
crops : beans, especially 
the broad bean, lima bean, 
beet, pea, celery, aspar- 
agus, orach, onion, leek, 
rhubarb and horse-radish. 
In England it has been 
reported as attacking 
turnip and parsnip. It 
is almost certain to be found in great abundance on nasturtium 
late in the season. Its common wild food plants are dock, 
burdock, lamb's quarters, shep- 
herd's purse and pigweed. 

The winter is passed in the 
egg stage on Evonymus, syringa, 
snowball and Deutzia. The 
egg is about -gV inch in length 
and shining black in color. The 
eggs hatch in early spring and 
the first generation develops on 
the tender foliage of these shrubs. 
When mature, the stem-mothers, 
as the aphids of the first gen- 
eration are called, give birth 
to living young, a few of which 
acquire wings. In the third 
generation a larger proportion 




Fig. 52. — Wingl;\ss vivip irons 
female bean aphis (X 20). 



PEA AND BEAN INSECTS 



77 



l)e('()me winged. The winged forms (Fig. 51) migrate to 
their summer food plants but the insect is capable of breeding 
the entire season on the plants on which it passed the winter. 
Throughout the summer the aphids 
reproduce parthenogenetically, all the 
individuals being females. Whenever 
the host plants become crowded, winged 
forms are produced that migrate to fresh 
feeding grounds. The full-grown wing- 
less viviparous female is about -^3 inch 
in length and blackish in color (Fig. 52). 
In the last nymphal stage of the winged 
form the abdomen is ornamented with 
five to seven pairs of white puh^erulent 
spots (Fig. 53). In the fall the winged 
forms fly back to their winter host 
plants and there produce yoimg that develop into wingless, 
egg-laying females. These are joined by winged males and after 
mating they deposit eggs in the crevices around the buds. 

The bean aphis can be killed by spraying with " Black Leaf 
40" tobacco extract, 1 part in 100 parts of water in which 
enough soap is dissolved to give a good suds. 




Fiu. 53. — Lufit nymphal 
stage of the winged 
viviparous female bean 
aphis (enlarged). 



The Garden Flea-Hopper 



Haliicus citri Ashmead 

This small black plant-bug resembles the cucumber flea- 
beetle in size, form and in its habit of jumping when disturbed. 
The female is dimorphic. In one form the wings are fully 
devel()])ed and in the other they are short and lack the mem- 
branous portion at the end. The long-winged form (Fig. 54) 
is ^ij inch in length, black in color, with the thorax and wings 
covered with small tufts of yellowish scale-like hairs ; the tip 
of the cuneus has a white spot. The legs and antennae are 



78 



MANUAL OF VEGETABLE-GARDEN INSECTS 




Fig. 54. — The Rarden flea-hopper, 
long-winged female (X 16). 



pale, marked with black. The short-winged form (Fig. 55) is 
somewhat smaller and more ovate in outline. The front wings 

lack the membranous part, 
do not extend to the tip of 
the abdomen and are rounded 
behind, thus resembling the 
wing-covers of a beetle. The 
male (Fig. 56) is similar to 
the long-winged female but is 
much narrower. 

The garden flea-hopper is 
generally distributed through- 
out the eastern United States 
and Canada, and westward to 
Kansas and Utah. It feeds 
on a great variety of plants 
including bean, pea, potato, 
tomato, eggplant, pepper, beet, cabbage, pumpkin, cucumber, 
squash, celery, lettuce, sweet potato, corn, clover, alfalfa, 
sweet clover and cowpea. Among 
its wild food plants may be mentioned 
beggarweed, ragweed, pigweed, plan- 
tain, smartweed, thistle, mare's tail, 
burdock, wild lettuce, vervain, stick- 
tight, self-heal, mallow, aster, oxalis 
and convolvulus. The garden flea- 
hopper has also been recorded as a 
pest of chrysanthemums and smilax 
in greenhouses. 

The life history of the garden flea- 
hopper is very imperfectly known. It 
seems probable that hibernation takes 
place in the egg stage on some of its perennial host plants, but 
in the South it may pass the winter in other stages. In 




Fig. 55. — The garden flea- 
hopper, short-winged fe- 
male (X 14). 



PEA AND BEAN INSECTS 



79 



Illinois the insects appear the middle of May, become abundant 
in July and are found on the plants until October. The eggs 
have not been described. The nymphs are pale green in 
color with darker wing-pads. The insects are found in all 
stages on the upper side of 
the leaves. They feed by 
jiuncturing the leaves and suck- 
ing out the sap, thus causing 
small round yellowish or whitish 
spots. The number of gen- 
erations a year has not been 
definitely determined but there 
are probably more than one. 

Control. 

When present in sufficient 
numbers to warrant the trouble 
the garden flea-hopper may be 
destroyed by spraying with 
"Black Leaf 40" tobacco extract, 1 pint in 100 gallons of 
water to wliich 5 or () pounds of whale-oil soap have been added. 




Fici. oG. — Tho gurdeii fk'ii-hoijpor, 
male (X !()). 



Reference 
U. S. Div. Ent. Bull. 19, pp. 57-G2. 1899. 



The Pea ^NIotii 

Crapholtta nigricann Stephens 

The pea moth is a European insect introduced into Canada 
some time before 1893. It is now distributed throughout 
eastern Canada, being especially injurious in the maritime 
provinces, and was reported as destructive in Michigan in 
1908. The moth has an expanse of about f inch. The front 



80 MANUAL OF VEGETABLE-GARDEN INSECTS 

wings are brownish gray with a nietalHc reflection. Along the 
front border is a series of short, oblique white and dark lines. 
The liintl wings are black with a bronzy reflection ; the fringe 
is white. The moths appear in late June and early July and 
lay their eggs during the evening on the recently set pods, 
depositing from one to three eggs on each pod. The eggs 
hatch in about two weeks and the young caterpillars imme- 
diately burrow into the pods. They feed on the developing 
peas, gnawing out irregular cavities and often webbing them 
together. The full-grown caterpillar is slightly hairy, about ^ 
inch in length and yellowish in color, with a black head and 
brownish cervical and anal shields. Affected pods usually 
ripen prematurely. When the pods open, the caterpillar 
descends to the ground and spins a silken cocoon a short dis- 
tance below the surface of the soil. Here the winter is passed 
either in the larval or pupal state, observers differing as to this 
point. There is but one generation annually. 

Control. 

In Canada it has been found that both very early and late 
peas are less liable to injury than mid-season varieties. Pre- 
liminary experiments indicate that the pest may be held in 
check by spraying with an arsenical at the time the pods are 
forming and by two later sprayings at intervals of ten days. It 
has also been suggested that deep fall plowing of the infested 
land would destroy many of the hibernating insects in their 
cocoons. Under ordinary farm conditions in America, the 
most practical measure is to adopt a crop rotation in which 
peas do not follow peas. 

References 

Curtis, Farm Insects, pp. 348-350. 1860. 

Ritzema Bos, Tierisehe Sehadlinge und Niitzlinge, pp. 474-47.5. 1890. 
Fletcher, Repts. Ent. Canada for 1894, p. 187 ; 1895, p. 138 ; 1897, 
p. 194 ; 1900, p. 214. 



PEA AND BEAN INSECTS 



81 



TiiK Bkan Leaf-Uolleu 

Eudanius prole us Linnseus 

The bean leaf-roller is a tropical insect ranging from Para- 
guay through ^Mexico and the West Indies to Florida and 
northward sometimes to New York and Connecticut. In the 
United States it has proved injurious only in Florida. Its 
injuries are usually confined 
to beans, though it is 
recorded as feeding on 
cowpea, turnip, cabbage 
and several species of 
Desmodium. Sometimes 
entire fields have been 
ruined by the attacks of 
this leaf-roller. 

In the extreme southern 
part of Florida and in the 
tropics, the insect breeds 
continuously throughout the 
year. In northern Florida Fig. 
it undoubtedly hibernates 
in the pupal stage. The first brood of butterflies appears in 
March. The butterfly has an expanse of about If inches. 
The wings are dark chocolate brown ; the front wings, are 
marked with several angular silvery white spots. The hind 
wings are furnished with long tails, somewhat similar to those 
of the swallowtail butterflies (Fig. 57). 

The butterfly lays its eggs singly or in groups of four to six 
on the underside of the leaves. Occasionally three to four eggs 
are piled one above the other in a vertical column. The egg 
is nearly globular, slightly flattened at both ends and marked 
with a series of delicate longitudinal ridges. It is nearly -^ 
inch in length. When first laid, the eggs are glistening white, 




The bean leaf-roller butterfly 
(X U). 



82 MANUAL OF VEGETABLE-GARDEN INSECTS 

gradually changing to a clear yellow. In summer the eggs 
hatch in four days and the young caterpillars immediately 
begin to eat out small i)atchcs in the surface of the leaves. 
Within a day after hatching, the larva constructs a retreat by 
folding over a flap of the leaf made by cutting along two lines 
converging from the margin. Within this retreat the larva 
lives, coming out only to feed. When about to molt, the edges 
of the retreat are sealed. In the third or fourth stage, the 
caterpillar constructs a new retreat by folding over a leaflet 
towards the middle"on the upper side. During the course of its 
development, the larva passes through five stages. The 
mature caterpillar is over 1^ inches in length. The head is 
brownish black and the body yellowish sprinkled with black, 
lighter below. The head is separated from the body by a 
distinct neck. The length of the larval period varies from 
two to three weeks. In Florida the life cycle requires about 
a month and there is, therefore, a possibility of eight or nine 
broods developing annually in that region. 

Under cage conditions, pupation occurs within the retreats 
and it is probable that this is the case in the open. The pupa 
is nearly an inch in length, greenish yellow at first, changing to 
shining brown. In two or three days it is covered with a white 
flocculent secretion. The pupal period occupies from six to 
ten days. 

Control. 

Experiments in Florida have shown that the caterpillars can 
be killed on beans by spraying with paris green. As this 
poison is likely to injure the plants, it would be better to use 
arsenate of lead (paste), -1 pounds in 100 gallons of water. 

References 

Scudder, Butterflies of Eastern U. S., 2, pp. 138G-1393. 1889. 
Fla. Agr. Exp. Sta. Bull. 45, pp. .^).5-60. 1898. 




PEA AND BEAN INSECTS 83 

The Striped Green Bean Caterpillar 

Ogdoconta cinereola Giicnee 

Bean vines are frequently stripped of their foliage and pods 
by a slender green caterpillar. This injury has been reported 
from Florida, Mississippi and Maine. 
The insect is generally distributerl 
throughout Canada and the United 
States east of the Rocky IMountains. 

The light brown moth has an 
expanse of about an inch. The 
front wings are marked with a 
few wavv gra^•ish white cross Fic. .5s. — The moth of tho 

lines. ACTOSS the outer margin «trii.cKl green bean catcrpiUur 

is a broad, light brownish gray 

band. The hind wings are brownish gray (Fig. 58). The 
moths are on the wing from June to September but it is not 
known where the eggs are deposited. The full-grown cater- 
pillar is over one inch in length, pale green, striped with whitish 
and yellowish longitudinal lines. This insect is related to the 
ca})bage looper and like it, the caterpillar has the habit of loop- 
ing like a measuring-worm. When disturbed the larvae give a 
series of violent jerks and fall to the ground. Pupation takes 
place in the soil. The pale yellowish brown pupa is slightly 
less than ^ inch long. Knowledge of the life history of this 
insect is very imperfect and additional observations should 
be made whenever opportunity offers. 

When abundant, the caterpillars may be destroyed by spray- 
ing with arsenate of lead (paste), 5 pounds in 100 gallons of 
water. On snap beans tobacco dust may be used to drive 
them from the plants. 

Reference 
U. S. Div. Ent. Bull. 14 (old ser.), p. 21. 1887. 



84 MANUAL OF VEGETABLE-GARDEN INSECTS 



The Gray Hair-Streak 

Uranotes melinus Hiibner 

One of the minor pests of the bean and pea is the shig-Uke 
caterpillar of a small, dainty butterfly, the gray hair-streak. 
It occurs throughout the United States, Central America, 
northern South America and the West Indies and is found 
rarely in southern Canada. It has been reported as injurious 
to beans or peas in New Jersey, Virginia, Maryland, Ohio and 
Colorado. In the South the caterpillars sometimes bore into 

cotton squares and okra pods 
and in the North they have 
been reported as feeding on 
the heads of the hop. Among 
wild plants, they feed on the 
following : Crataegus, St. John's- 
wort, hound's tongue, bush clover, 
loco-weed, tick trefoil, and Japan 
plum. 

The butterfly has an expanse 
of li inches. The upper surface 
of the wings is blackish tinted with blue-gray. The hind 
wings have near the hind angle a row of bluish spots, in the 
center of which is a large orange spot surrounding a small 
black one. On the outer margin there are in the male one, and 
in the female two, small tail-like processes. The under surface 
is gray with two blackish brown lines crossing each wing 
(Fig. 59). The butterflies are on the wing from May to 
September in the North and March to November in the 
South. The eggs are small and pea-green in color. Where 
they are deposited and the time of incubation have not been 
determined. The caterpillars bore into the pods of peas and 
beans and destroy the developing seeds. The full-grown 
caterpillar is green, about i inch in length, and slug-like in 




Fig. 59. • — The gray hair-streak 
butterfly (X U). 



PEA AND BEAN INSECTS 85 

appearance. The chrysalis is iialved, and hangs freely, at- 
tached at the caudal end to a hutton of silk. The pupal 
period lasts from ten days to two weeks. In the North 
there are two, and in the South, three broods annually. 

If necessary, the caterpillars may readily be controlled by 
spraying with an arsenical. 

References 

Seudder, Butterflies of Eastern U. S., 2, pp. 850-855. 1889. 
U. S. Div. Ent. Bull. 33, pp. 101-102. 1902. 

The Green Clover Worm 

Plathypena scabra Fabrieius 

This insect is common throughout the eastern United States 
and Canada. Its favorite food plant is clover but occasionally 
the caterpillars defoliate peas, beans and lima beans. They 
are also found on tickweed, soybeans, vetch and strawberry. 

The moths have an expanse of 1 to 1-j inches, the larger 
specimens usually being males. The palpi form a rather 
prominent snout. \Yhen at rest, the wings are closely ap- 
pressed to the body. The front wings are blackish brown, 
the outer part of the wing in the female shaded with light gray 
and often with brown. The wing is crossed near the middle 
by a fine black line which is wavy and often very faint on the 
front half but straight and composed of raised black scales on 
the posterior half. At one quarter and at three quarters the 
distance from the base of the wing is a fainter wavy dark line 
and at one third the distance a raised black dot. Some females 
are marked with one or two longitudinal black dashes. The 
hind wings are blackish brown (Fig. GO). 

The moths emerge from hibernation in early spring. In 
Washington, D. C, they are on the wing in warm sunny days 
even in the winter. In that latitude there are three genera- 



86 MANUAL OF VEGETABLE-GARDEN INSECTS 

tions annually ; the first brocid of caterpillars becoming mature 
about the middle of June, the second early in August and the 
third in late September or early October. The caterpillar is 
slender and loops with the front half of the body when walk- 
ing. In the next to the last stage, it is nearly an inch in length, 
pale green in color and striped lengthwise with fine white or 
cream-colored lines. In the last stage it is nearly uniform pale 
green, the stripes having become much less distinct. The 
caterpillars mature in about twenty-five days and then con- 
struct cocoons in leaves webbed 
together with silk within which 
S^[^^^^/^^^|^i| they transform to dark brown 
^I^^^BBK^^^^ pupse about ^ inch in length. The 
^^^^HWj^HBj^ moths emerge in eight days to two 

^(Hpr^Hj^^ weeks and lay eggs for another 

")rood. The egg is about -gV inch in 



Fig. 60. — The moth of the diameter, globular, flattened above 

green clover worm (X 11). . , . , i- • 

and with coarse ridges radiating 
from the apex. The eggs hatch in four to six days and the 
young caterpillars feed on the underside of the bean leaves, 
eating out irregular holes and when abundant stripping the 
plants of their foliage. Sometimes the caterpillars also eat 
holes in the pods. 

When attacking shell beans, the caterpillars may be poisoned 
by spraying the vines with arsenate of lead (paste), 2 pounds 
in 50 gallons of water, taking care to apply the spray to the 
underside of the leaves. On string or snap beans, tobacco 
dust or extract may be used. It has also been suggested that 
many of the caterpillars could be killed by spraying the un- 
derside of the leaves with a strong soap solution; 

References 

U. S. Div. Ent. Bull. 30, pp. 45-50. 1901. 
Conn. Agr. Exp. Sta. Rept. for 1908, pp. 828-832. 



PEA AND BEAN INSECTS 87 

The Lima Bean Vine-Borer 

Monoptilota nubilella Hulst 

From Maryland to Florida and Alabama, pole varieties of 
lima beans are occasionally infested by a caterpillar that bnr- 
rows in the stalk, causing a gall-like enlargement which is about 
1| inches in length by ^ inch in diameter. These galls may 
occur at any point from the surface of the ground to near the 
tip of the vine. The injury inflicted varies with the position 
of the gall and with the thriftiness of the vine. When the 
caterpillar enters a well-formed stalk, the plant is not seriously 
affected, but when the gall is fyrmed in small stalks near the 
tip, the terminal portion often wilts and dies or at least is not 
able to produce full-sized pods. The full-grown caterpillar is 
about f inch in length and of an unusual color for a borer, 
being a beautiful blue-green, tinged with pinkish above. When 
mature, it leaves the gall and pupates on or in the ground in 
an oval silken cocoon covered with particles of dirt. The pupa 
is dull olive-brown and a little less than ^ inch in length. Some 
of the moths may emerge the same summer and lay eggs for a 
second brood. The moth has an expanse of about | inch. 
The front wings are brownish gray shaded with whitish especially 
toward the base near the front margin and are marked with 
several small blackish streaks about one third the distance 
from the base of the wing. The hind wing is translucent white 
in the male and dark in female. 

Xo better treatment is known than to kill the caterpillars 
with a knife while still in their burrows. 

Reference 
U. S. Div. Ent. Bull. 23. pp. 0-17. 1900. 

Other Pea and Bean Insects 

Corn ear-worm : 211 
Southern corn root-worm : 222 



88 MANUAL OF VEGETABLE-GARDEN INSECTS 

Cabbage looper : 8 

Garden webworm : 18 

Seed-corn maggot : 36 

Western radish maggot : 37 

Harlequin cabbage bug : 38 

Green soldier-bug : 42 

Red turnip beetle : 50 

Yellow bear caterpillar : 357 

Salt marsh caterpillar : 359 

Sugar-beet webworm : 97 

Western twelve-spotted cucumber beetle : 114 

Belted cucumber beetle: 115 

Diahrolica connexa: 116 

Diahrotica picHcornis : 110 

Melon leaf-bug: 121 

Southern leaf -footed plant-bug : 121 

Melon aphis : 135 

Garden springtail : 139 

Potato aphis : 150 

Common stalk-borer : 157 

Spotted cutworm : 262 

Well-marked cutworm : 263 

Greasy cutworm : 265 

Dark-sided cutworm : 268 

Striped cutworm : 270 

Dingy cutworm : 271 

Granulated cutworm : 273 

Clay-backed cutworm : 274 

Black army-worm : 275 

Variegated cutworm : 276 

Gla&sy cutworm : 279 

Clover cutworm : 284 

Army cutworm : 287 

Army-worm : 288 

Beet army-worm : 294 

Striped blister-beetle : 302 

Margined blister-beetle : 305 

Gray blister-beetle : 306 

Ash-gray blister-beetle : 306 

Nuttall's blister-beetle : 308 

Spotted blister-beetle : 309 

Two-spotted blister-beetle : 309 

Western potato flea-beetle : 318 

Pale-striped flea-beetle : 321 

Red-headed flea-beetle : 323 



I 



PEA AND BEAN INSECTS 89 



Smartweed flea-beetle : 323 
Western cabbage flea-beetle : 327 
Desert corn flea-beetle : 334 
Root-knot nematode : 338 
Millipedes: 342 
Slugs: 354 
Red-spider : 351 
Wheat wnreworm : 348 
Sugar-beet wireworm : 349 



CHAPTER IV 
BEET AND SPINACH INSECTS 

The insects attacking beet and spinach, as a rule, also feed 
on related wild plants, chiefly various species of Chjienopodium 
and Amaranthus. ]\Iany of these plants are common weeds 
and serve as centers from which infestation spreads to culti- 
vated crops. Over one hundred and fifty insects have been 
recorded as feeding on sugar-beets, about forty of which are 
considered as important pests. The sugar-beet is classed as a 
field crop and in this chapter only those insects are treated 
which have been found causing important injury to garden 
beets and spinach. The two principal insect pests of spinach 
are the leaf-miner and the aphis, their combined attacks often 
making the growing of this crop unprofitable in certain localities. 

The Spinach Leaf-Miner 

Pegomyia hyoscyami Panzer 

This troublesome pest of beets and allied crops is present in 
both Europe and America. In Europe the insect has been 
known for over a century and in this country it first attracted 
attention by its injuries about ISSO. It is now generally dis- 
tributed throughout the United States and Canada. The 
maggots infest the leaves of spinach, orach, beets, sugar-beets, 
mangels and chard. Its other food plants are lamb's quarters, 
and in the British Isles and Europe deadly nightshade, henbane, 

90 



BEET AND SPINACH INSECTS 



91 




Fig. G1. — The spinach leaf-minor, adult 
(X4). 



nettle-leaved goosefoot, common chickweed and lady's thumb 
{Pohigon u m pcrsicaria) . 

The flies appear in the fields in April or May. They are 
about \ inch in length, grayish in color and clothed with numer- 
ous black setoe ; the legs 
are yellowish with the 
tarsi blackish (Fig. Gl). 
The female deposits her 
eggs singly or in rows of 
two to five placed side 
by side on the underside 
of the leaves (Fig. 02). 
The egg is about ^V "^t-h 
in length, white, cylin- 
drical, and the surface 
is distinctly reticulated. 
The eggs are attached 

to the leaf by one side ; they hatch in four to six days and 
the young maggot works its way into the tissue of the leaf 
where it eats out a mine between the upper and lower epi- 
dermis. The mine is at first thread-like but is soon enlarged 
to form a blotch. Several maggots usually 
occupy the same leaf and their mines usually 
coalesce. In the course of its growth the 
maggot molts twice, thus passing through 
three stages. If the ff)od material in a single 
leaf becomes exhausted, the maggots may 
; iG. 62. — Eggs migrate to another leaf in order to complete 
of the spinach ^hcir growth. In case the leaf dies, the mag- 

leaf-miner (X ,, , i-ii 

31). gots are able to complete their development 

on manure or humus, according to observations 

made in Hungary. The larva becomes full-grown in a week 

to sixteen days. It is then ^ inch in length, white or 

yellowish with the hook-like mouth-parts black. The body 




92 MANUAL OF VEGET ABLE-GARDEN INSECTS 

tapers towards the head and is obHquely truncate posteriorly. 
When mature, the hir\a usually deserts the leaf and enters 
the earth, where, at a depth of two or three inches, it changes 
to a brownish puparium, about ^ inch in length. Sometimes 
the puparia are founii in the dead and rotting leaves on the 
ground. The flies emerge in two weeks to twenty-five days 
and soon lay eggs for another brood. In central New York 
there are three generations and a partial fourth annually. 

The spinach maggot is most injurious to spinach and chard, 
and beets when used for greens. The injury to the leaves of 
beets, mangels and sugar-beets also decreases the size of the 
root-crop. When these crops are grown for seed, the quantity 
produced is often seriously lessened by the partial defoliation 
of the plants by the maggots. 

Control. 

No satisfactory method of preventing the damage by the 
spinach leaf-miner has as yet been devised. Clean culture and 
the destruction of the insect's wild food plants, lamb's quarters 
and other weeds will be of some value in decreasing the degree 
of infestation. In some localities growers avoid a bad infes- 
tation in spinach by growing the crop late in the fall and early 
in the spring. 

References 

N. Y. (Geneva) Agr. Exp. Sta. Bull. 99. 1896. 

Jablonowski, Tieresehen Feinde der Ziickerrube, pp. 303-315. 1909. 

Cameron, Ann. Appl. Biol., 1, pp. 43-76. 1914. 

The Beet Leafhopper 

Eutettix tenellus Baker 

In the western states from Idaho, Nebraska and Texas, 
westward to the Pacific and southward into Mexico, sugar- 
beets, table beets and mangels are subject to a disease known 
as curly-leaf, the exact cause of which is not fully understood. 



BEET AND SPINACH INSECTS 93 

Diseased plants have the veins of the leaves enlarged, and the 
surface becomes warty, uneven, and the edges curl inward, 
bringing the under surface into view. The petioles are shorter 
and bowed outward. The leaves are more brittle than normal, 
although they have a leathery appearance. Young plants 
may be killed outright, others are badly stunted ; the sugar- 
content of the roots is lessened and there is an abnormal de- 
velopment of rootlets. Cross-sections of the root often show 
dark concentric circles from the darkening of the fibrovascular 
bundles. Frequently large fields of beets so affected are not 
worth harvesting and in many localities the growing of sugar- 
beets has been abandoned for this reason. When beets are 
grown the second year for seed, the presence of this disease 
greatly reduces the crop. 

The disease is transmitted by a small, creamy or greenish 
white leaf hopper, sometimes tinged with red, about ^ inch in 
length, both nymphs and adults being capable of infecting 
the plant on which they feed. This insect is a native of the 
same region where it feeds on several species of Atriplex and 
Russian thistle, sea blite and greasewood. Certain species of 
Atriplex seem to be its favorite wild food plants. The insect 
hibernates as an adult, appearing in the beet fields in late 
spring. 

Beet fields do not, as a rule, become infested by leaf hoppers 
that have hibernated in their immediate ^•icinity. Apparently 
the infestation comes from leaf hoppers that have developed on 
their wild food plants in desert regions and that have hiber- 
nated near their breeding groimds. In late spring these insects 
migrate in great swarms, passing over high mountain ranges 
and traveling to distances of several hundred miles. In the 
course of the migration, the leafhoppers settle in any beet 
fields in which the plants are in condition to serve as food. If 
the crop in a field is not up at the time of the flight, it is not 
likely to become infested from adjoining fields but may be 



94 MANUAL OF VEGETABLE-GARDEN IN,SECTS 

attacked by a later flight if a second migration occurs. Injury 
by the leafhopper is hkely to take place in regions not infested 
the previous year and a season of severe injury may be fol- 
lowed by one in which practically no leafhoppers can be found. 
In most localities the disease is of a periodic nature, but in 
certain regions within the permanent breeding area infestation 
is almost sure to occur every year. 

In feeding, the insect punctures the leaf with the slender 
needle-like bristles of its beak and sucks out the juices of the 
plant, at the same time inoculating it with the virus of the 
disease. When disturbed, the leafhoppers spring quickly into 
the air and take wing, but soon alight seeking shelter on another 
plant. When on the wing they appear white. The female 
inserts her eggs their full length singly in the stems, midrib 
and petiole of the leaves and sometimes in the larger side veins. 
The eggs are pale, elongate, slightly curved and narrower 
anteriorly. Before hatching the growth of the leaf usually 
forces the eggs part way out of the tissue. The eggs hatch in 
about two weeks and the minute, nearly colorless nymphs begin 
feeding on the leaves down in the center of the plant. The 
older nymphs vary from creamy Avhite in color to nearly black, 
variously spotted and mottled with brown, buff and red. 
In about three weeks the nymphs become mature, having 
passed through five immature stages in the course of their 
growth. The eggs are laid during a considerable period, from 
late in June to the first of September in the northern part of 
the insect's range, but the greater number are deposited during 
the first half of July. Each female is capable of laying about 
80 eggs. There is only one generation annually. 

The control of this leafhopper and the consequent elimina- 
tion of the curly-leaf disease is commercially unsolved. The 
adult hoppers are hard to hit and difficult to kill with contact 
insecticides and it is doubtful whether spraying would be com- 
mercially profitable. Something can be gained, however, by 



BEET AND SPINACH INSECTS 



95 



early planting:; aiul hy <;()()(1 care of the erop early in the season 
so as to get the plants well established before the hopj)ers make 
their appearanee in the field. 



References 

U. S. Bur. Ent. Bull. GG, pp. 33-52. 1909. 
U. S. Bur. Plant Ind. Bull. 181. 1910. 
Utah Agr. Exp. Sta. Bull. l.'>r>. 1917. 



The Lakger SiTrAR-BEET Leaf-Beetle 

Monoxia puncticollis Say 

In New ]\Iexico, Colorado and .Montana, sngar-beets are 
sometimes attaeked by the larvte and adults of this leaf-beetle, 
but it has not yet been reported as an enemy of table beets. 
Its wild food plants are sea blite, 
Russian thistle and salt-bush. Both 
larvie and adults feed on the leaves 
but the greater part of the injury is 
caused by the former. When dis- 
turbed they fall readily to the 
ground. The beetle occurs along 
the Atlantic and Gulf coast and 
westward to California, and north- 
ward through Colorado, Utah and 
Montana. It is ^ to ^ inch in 
length, and varies considerably in 
c )lor, from uniform dull yellowish 

brown to nearly black ; in some forms each wing-cover is 
marked with one or two more or less distinct dark stripes 
(Fig. 63). The insect hibernates in the beetle stage, appear- 
ing on its food plants early in the spring. The female de- 
posits her eggs, a little less than ^ inch in length, in irregular 
clusters of two or three to fort\' or fiftv on the leaves. These 




Fig. 6.3. — The larger sugar- 
beet leaf-beetle (X 4D- 



96 



MANUAL OF VEGETABLE-GARDEN INSECTS 



hatch hi about a week and the larvae begin feeding on the 
leaves. The young larva is about yV inch in length, dull gray, 
with the thoracic shield and the areas at the base of the tubercles 
dark brown. The larva becomes full-grown in nine or ten 
days. It is then about f inch in length, dark olive brown with 
the tubercles pale yellow. The larvae enter the ground for 
pupation and the beetles emerge a few days later. There are 
two generations annually. 

It has been observed in Colorado that the insect is most 
troublesome on beets grown on or near alkali ground. 



References 

U. S. Div. Ent. Bull. 40, pp. 111-113. 1903. 
Gillette, Kept. State Ent. Col., pp. 8-11. 1903. 



The Western Beet Leaf-Beetle 



Monoxia co7isputa Leconte 

This leaf-beetle ranges from California and Oregon east to 
the Dakotas and Kansas. It has been 
reported as injurious to beets and sugar- 
beets in California and Oregon. Both 
larvae and adults feed on the leaves, 
leaving only the larger veins. The 
beetle (F'ig. 64) is nearly ^ inch in 
length, yellowish brown ; the wing- 
covers are sometimes marked with 
small scattered black spots often 
arranged in rows. 

The beet leaf-beetles can be con- 
trolled by thoroughly spraying the plants with arsenate of 
lead (paste), 5 or 6 pounds in 100 gallons of water. 




Fk;. 04. — The western 
beet leaf-beetle (X 51). 



BEET AND SPINACH INSECTS 97 

The Sucak-Bkkt Wkhwokm 

Loxoslege sticHcalis Linnaeus 

Although the sugar-beet webworm has attracted more atten- 
tion as an enemy of the sugar-beet, it also attacks a large num- 
ber of garden and field crops. It is widely distributed through- 
out Europe, Asia and North xA.merica and is particularly 
injurious in southeastern Europe. It did not attract notice in 
the United States until the beginning of the development of 
the sugar-beet industry. It has been destructive only in the 
Mississippi \'alley and westward to the Rocky JNIountains. 
In addition to the sugar-beet, it has been reported feeding on 
the following : pea, bean, potato, cabbage, onion, squash, 
pumpkin, cucumber, alfalfa and vari- 
ous grains and grasses. Its favorite 
wild food plants are pigweed (Ama- 
ranthus) and lamb's quarters. 

The winter is passed by the full- 
grown caterpillars in silken tubes in 

thp soil In latp snrinp- thev trans- Fig. 65. — The sugar-beet 
tne soil, in late spring ine\ irans webworm moth (x li). 

form within the tubes to yellow-brown 

puppe about ^ inch in length. In about eleven days the moths 
emerge. The moth has an expanse of about an inch. The 
front wings are smoky brown with faint darker markings, a 
straw-colored spot below the middle of the front margin and 
a similarly colored band along the outer margin. The hind 
wings are paler with two blurred bands (Fig. G5). The 
females deposit their pale, pearly green or yellow, oval eggs 
about ^ inch in diameter, singly (;r in overlapping rows of 
two to ten, usually on the underside of the leaves. The egg 
is flattened below and very convex above. Each female lays 
from 200 to 250 eggs. The eggs hatch in three to five 
days. The young whitish larvse with black heads feed at 




98 MANUAL OF VEGETABLE-GARDEN INSECTS 

first on tlic soft tissues on the underside of tlie leaves. As 
they increase in size, they l)ecome yellowish ^reen in color 
with dark markings and consume almost the entire leaf. The 
caterpillars feed by preference on the older, outer leaves and do 
not attack the newer leaves at the center of the plant until 
the others have been consumed. Their feeding grounds are 
covered by a slight silken web. The full-grown caterpillar is 
about an inch in length, yellowish white with a broad black 
median stripe and a broader sub-dorsal stripe and marked with 
numerous piliferous spots surrounded by black rings. The 
larva becomes mature in about three weeks and constructs a 
silken tube in the ground within which it forms a cocoon and 
pupates. The winter cocoon is about three times the length 
of the larva and the summer cocoon only twice as long. There 
are usually three generations a year and in some cases a small 
fourth brood may occur. A few of the first, a considerable 
part of the second, and nearly all of the third generation cater- 
pillars do not transform till the following spring. The first 
brood are destructive while the sugar-beet plants are small and 
easily killed. At this time the crown of the plant is often 
attacked. When the later broods appear, the plants are larger 
and rarely killed outright but the size and sugar-content of the 
roots are greatly decreased by the defoliation of the plants. 
The third brood is the least injurious because the plants are 
more nearly mature and the brood is smaller. 

In some regions in which the sugar-beet is grown extensively, 
the caterpillars often occur in coimtless numbers and the moths 
attract attention by flying in clouds over the fields. 

Means of control. 

The sugar-beet w^ebworm may be controlled on sugar-beets 
by thorough spraying with .3 pounds of paris green in 100 gallons 
of water to which 6 pounds of whale-oil soap or 3 pounds of 
lime are added as an adhesive. About 100 gallons of the mix- 



BEET AND SPINACH INSECTS 99 

ture should be applied to the acre and the application should 
be made as soon as possible after the caterpillars have hatched. 
The s{)ray should be applied with at least SO pounds' pressure. 
Recent experiments in Colorado and Kansas have shown that 
paris green applied in this way will satisfactorily control the 
webworm on beets and is much more effective than arsenate of 
lead. In some cases in which the ground is too wet for the use 
of a sprayer, paris green may be applied in the form of a dust 
at the rate of 2 to 4 pounds in 100 pounds of air-slaked lime. 

References 

Koppen, Die Shadlichcn Insokton Russlands, pp. 394-405. 1880. 
Rilev, Rept. U. S. Ent. for 1892, pp. 172-175. 
Col. Agr. Exp. Sta. Bui. 98, pp. 2-12. 1905. 
U. S. Bur. Ent. Bui. 109, pp. ,57-70. 1912. 

The Hawaiian Beet Webworm 

Hymenia fascialis Cramer 

In the southern United States beet leaves are sometimes 
skeletonized on the underside by a small, slender, pale green 
caterpillar which has received the rather inappropriate com- 
mon name given above. The insect ranges throughout the 
southern states westward to California. It is also generally 
distributed throughout the warmer parts of the Old World. 
Its habits and life history have been studied carefully in 
Hawaii. In that climate, breeding is continuous throughout 
the year. Its food plants include table beets, sugar-beets, 
Swiss chard, mangels and Amarantus gancjeticus, a Chinese pot- 
herb sometimes known as spinach. Among weeds, it feeds on 
purslane and numerous species belonging to Amaranthus and 
Chsenopodium. The caterpillars reach maturity in nine days 
to two weeks and then enter the ground a short distance, where 
they form firm, oblong earthen cocoons composed of silk and 



100 MANUAL OF VEGETABLE-GARDEN INSECTS 

particles of earth. The pupa is f inch in length and pale brown 
in color. The moths emerge in a week or two. The moth has 
an expanse of about f inch. The wings are uniform blackish 
brown. The front wing has a broad translucent white band 
across the middle, not quite reaching the front margin. Two 
thirds the distance to the outer margin a wdiite bar extends 
halfway across the wing. The hind wing is crossed by a nearly 
even white band. The moths are shy and are usually to be 
found hiding under the leaves. In Florida they are often found 
in great numbers feeding on the nectar of catnip blossoms. 
The female deposits her minute elliptical flattened eggs, about 
4V ii^ch in length, singly or in short rows on the underside of 
the leaves. The eggs hatch in about four days. The cater- 
pillars sometimes spin a slight web over their feeding grounds 
but more often feed openly. It is believed that in Hawaii 
from six to ten generations may be produced annually. 

This webworm can be controlled by spraying with arsenate 
of lead (paste), 2 pounds in 50 gallons of water, taking care to 
coat the underside of the leaves. 

Reference 
U. S. Bur. Ent. Bull. 109, pp. 1-15. 1911. 

The Spotted Beet Webworm 

Hymen a perspcctalis Hiibner 

The spotted beet webworm is widely distributed throughout 
the warmer parts of the world and in the United States is 
sometimes found out of doors as far north as Virginia. In 
greenhouses it often proves a troublesome pest on Alternanthera. 
In the open it sometimes becomes destructive to beets, sugar- 
beets and Swiss chard. The moth has an expanse of about |- 
inch. The wings are blackish brown shaded with clay-color, 



BEET AND SPINACH INSECTS 101 

especially on the hind wings. The markings are translucent 
white ; on the front wing there is a narrow^ curved line near the 
base ; a nearly square patch at the middle near the front edge ; 
a line running from close to this to the hind margin, and two 
thirds the distance to the outer margin a white bar extends 
halfway across the wing. Across the middle of the hind wing 
is an irregular white band, narrower behind. 

The moth deposits her flat, oval, semi-transparent, greenish 
eggs, about ^V "i^ch in length, singly on the stems of the plant, 
usually near the base. The young larvae at first skeletonize 
the leaves but later devour the whole leaf. The full-grown 
larva is a little more than ^ inch in length, shining green and 
marked with rows of small black spots. Pupation takes place 
in a thin loose silken cocoon on the ground at the base of the 
plants. The pupal period occupies from one to three weeks, 
depending on the season. Under greenhouse conditions the 
life cycle is completed in two or three months. 

The spotted beet webworm may be controlled by the meas- 
ures suggested for the preceding species. 

References 

Davis, 27th Kept. State Ent. 111., pp. 103-106. 1912. 
U. S. Bur. Ent. Bull. 127, pp. 1-11. 1913. 

The Southern Beet Webworm 

Pachyzancla bipunctalis Fabricius 

In Georgia, Florida and Texas, this webworm has been re- 
ported as occasionally injurious to beets, cauliflower and cab- 
))age. Its wild food plants include ragweed, spiny amaranth 
and Amarantus retroflexus. The insect ranges southward 
through the West Indies into South America and also occurs 
in South Africa. The caterpillars feed on the leaves of their 
food plants, folding and webbing them together with silken 



102 MANUAL OF VEGETABLE-GARDEN INSECTS 

threads. The full-grown larva is a})out f ineh in length, dark, 
dirty green with the head and the sides of the cervictd shield 
dark brown. The surface of the body is semi-transparent and 
glossy in appearance. The caterpillars become mature in two 
or three weeks and transform to mahogany brown pupiie f 
inch in length. The posterior end of the body is prolonged into 
a bill-like process bearing four pairs of recurved hooks. The 
pupal period occupies about eight days in warm weather. The 
moth has an expanse of about an inch. The front wings vary 
from bufl' to pale yellowish gray, often tinged with purplish 
and crossed by two irregular brownish lines and marked with 
two black dots near the front margin. The moth deposits her 
eggs singly on the underside of the leaves. The eggs are 
flattened, irregularly oval, yellowish or greenish in color and 
about eV ii^f^li in length. They hatch in about a week. There 
are thought to be four generations a year. 

This beet webworm may be controlled by the measures sug- 
gested for the Hawaiian beet webworm. 

Reference 
U. S. Bur. Ent. Bull. 109, pp. 17-22. 1911. 

The Sugar-Beet Root-Louse 

Pemphigus helm Doane 

In the western United States from western Kansas and 
Nebraska to California, sugar-beets, beets and mangels often 
have the roots infested with a small, pale yellow plant-louse. 
In the case of sugar-beets, not only does the presence of the 
plant-lice greatly decrease the weight but also the sugar- 
content of the roots, in many localities making it unprofitable 
to grow the crop. This root-louse is a native of the western 
United States, where it is found most abundant on the roots of 



BEET AND Sl'INACII INSECTS 103 

lamb's quarters but has also been reported as infesting the 
roots of the following plants : yarrow, knotweed, dock, aster, 
goldenrod, horse-weed, winged pigweed, foxtail, salt-grass, 
blue-joint grass, wheat, flax and alfalfa. 

The insect passes the winter in two forms, either as wingless 
viviparous females on the roots of its food plants or as eggs on 
the liark of two species of cottonwood {Populus angu.siifoUa 
and P. halsamifera) . The plant-lice that have survived the 
winter on the roots begin to give birth to living young in April 
or May, producing another generation of wingless viviparous 
females. Reproduction continues in this way until mid- 
summer, when winged forms begin to appear. Only about half 
of the lice acquire wings, the others continue breeding on the 
roots throughout the season. The form found on the roots is 
about \ inch in length, pale yellow in color and has the pos- 
terior part of the abdomen clothed with a white flocculent mass 
of waxy filaments. The remainder of the body is dusted with 
a white powder. Infested roots appear to be covered with a 
white or grayish mold. The winged forms produced on the 
roots are slightly larger than the wingless forms. The abdo- 
men is greenish, the thorax, head and antennae bluish black, 
lightly dusted with the whitish powder and there is only a 
little of the white flocculent material on the tip of the body. 
These winged forms begin to appear in midsummer and con- 
tinue until the end of the season but are most abundant in 
September and October. They migrate to the cottonwood, 
where, on the bark of the trunk, each female gives birth to four 
to seven young, part males and part females, the latter pre- 
dominating. These forms lack functional mouth-parts and do 
not take food. They molt four times in as many days and 
after mating the female deposits a single pale yellow egg in a 
crevice of the bark, which usually rests on a mass of bluish 
white waxy threads. The eggs hatch about the first of the 
following jNIay and the young plant-louse crawls out on the 



104 MANUAL OF VEGETABLE-GARDEN INSECTS 

upper side of an opening leaf, where it establishes itself and 
begins feeding. A depression soon appears on the leaf at this 
point which gradually develops into a pocket-like outgrowth 
on the underside opening by a narrow slit in the upper side. 
Within this pocket-like gall, the plant-louse becomes mature 
and gives birth to seventy-five to one hundred and seventy- 
five young, all of which acquire wings and on escaping fly to 
beets or other food plants, where they produce young which 
descend to the roots. This migration from the cottonwood 
takes place mostly in July. Beets become infested both from 
lice living over in the ground on last year's crop or on weeds, 
and by the migrants from the cottonwood. 

The only practicable measure so far suggested for the con- 
trol of the sugar-beet root-louse can be employed only where 
irrigation is practiced. It consists in giving the plants the 
maximum quantity of water that they can stand, thus forcing 
the growth and at the same time producing conditions unfavor- 
able to the multiplication of the insects. 

Beets are also sometimes infested by another species of root- 
louse, Tychea brevicornis Hart. This peculiar plant-louse is 
wingless, with the abdomen very large and without cornicles. 
Corn, sorghum, salt-grass, pigweed, purslane, mustard, lettuce 
and dock have been recorded as hosts of T. brevicornis. 

A closely related species, determined as the European T. 
pha-scoli Passerini, has been reported as feeding on the roots of 
bean and clover. There is some doubt as to the determina- 
tion of the species of plant-lice found on the roots of many of 
our common weeds and vegetables. They are in great need of 
further study. 

References 

Wash. Agr. Exp. Sta. Bull. 42. 1900. 

Parker, Jour. Econ. Ent., 7, pp. 136-141. 1914. 

Parker, Jour. Agr. Research, 4, pp. 241-250. 191.5. • 

Maxson, Jour. Econ. Ent., 9, pp. 500-505. 1916. 



BEET AND SPINACH INSECTS 105 

The Spinach Aphis 

Myzus 'persicce Sulzer 

The spinach aphis is also known as the green peach aphis, 
and as the common green-fl}^ of greenhouses. It is found in 
both Europe and America. In some locaHties it is the most 
serious insect enemy of spinach and is sometimes injurious to 
potato, tomato, eggplant, cabbage, turnip, radish, cauliflower, 
cucumber, kale, mustard, beet, rutabaga, water cress, pepper, 
horse-radish, celery, rhubarb, okra and lettuce. Eggplant often 
becomes infested in the hot-bed before transplanting. Radishes 
and rutabagas are sometimes attacked as soon as they come 
up, the first pair of leaves being entirely covered on the under- 
side by the lice. Such plants are badly stunted and sometimes 
killed. The spinach aphis also attacks a number of w^eeds, 
including pigweed, lamb's quarters, dock, shepherd's purse, 
dandelion, sow thistle, lupine and wild mustard. It is often 
found in greenhouses, where it infests the calla lily, carnation, 
rose, violet, oleander and many others. It has also been re- 
corded from tulip, pansy, hollyhock, tobacco, peppermint, rape 
and several ornamental plants. It is also sometimes found in 
the summer on apple, pear and lilac. 

The spinach aphis may pass the winter either in green- 
houses or on its food plants out of doors, where the winters are 
not too cold, or in the egg stage on the peach, plum, cherry, 
apricot, sand cherry and choke cherry. In the last case, the 
eggs hatch shortly before the buds burst in the spring and the 
stem-mothers are ready to begin reproduction when the blossoms 
appear. They are wingless and of a pinkish color. In the 
second generation the ])lant-lice are for the most part wingless, 
but instead t)f being pink, are pale yellowish green and usually 
marked with three indistinct darker stripes on the abdomen. 
In the third generation, most of the lice acquire wings. They 



106 MANUAL OF VEGETABLE-GARDEN INSECTS 




are then greenish with the head, thorax and a large spot on the 
abdomen black. These winged forms leave the tree and fly 
to their various herbaceous food plants where they found colonies 
of young. When the lice have survived the winter on weeds 

or vegetables, reproduction is resumed 
as soon as new growth starts in the 
spring. They multiply rapidly and 
the plants soon become covered with 
the lice. The wingless forms found 
on the summer food plants have the 
bofly a uniform greenish yellow, 
without the darker lines found on 
the forms on the peach, or plum 
(Fig. 66). When the plant becomes 
Fig. 66. — Wingless viviparous crowded, winged forms (Fig. 67) are 

female spinach aphis (X 11). , i i • i • pi 

produced which migrate to new feed- 
ing grounds. The insects are most destructive to spinach 
late in the season when the cooler weather prevents the rapid 
multiplication of their predaceous and parasitic enemies, 
although they may become troublesome at any time. In the 
fall some of the winged females return to the peach, j^hmi ( r 
cherry, establish themselves 
along the veins on the un- 
derside of the lea^■es and 
give birth to true or ovipa- 
rous females. The latter are 
usually of a pinkish color, 
similar to the stem-mothers 
of the preceding spring. 
After pairing with the 

winged males, they deposit their eggs in the axils of the buds 
and in crevices of the bark. The eggs are small, oval and 
shining black, and closely resemble those of the common green 
apple aphis. 




Fig. 67. — Winged viviparous female 
spinach aphis (X 7^). 



BEET AND SPINACH INSECTS 107 

Control. 

The spinach aphis is readily killed when hit by spraying with 
"Black Leaf 40" tobacco extract, 1 pint in 100 gallons of 
water to which 5 or 6 pounds of soap have been added. On 
spinach, however, and other plants the leaves of which lie close 
to the ground, it is not easy to obtain satisfactory control 
owing to the difficulty of wetting the underside of the leaves 
with the spray. 

References 

Taylor, Jour. Eeon. Ent., 1, pp. 83-91. 1908. 
Col. Agr. Exp. Sta. Bull. 133, pp. 32-37. 1908. 
Va. Truck E.xp. Sta. Bull. 2, i)p. 30-32. 1909. 

Other Beet and Spinach Insects 

Southern corn root-worm : 222 

CaV)bage looper : 8 

Cabbage webworm : 16 

Garden webworm : 18 

Harlequin cabbage bug : 38 

Serpentine leaf-miner : 4() 

False ehinch-bug : 47 

Yellow bear caterpillar : 3")7 

Carrot beetle : 185 

Celery leaf-tyer : 189 

Celery looper : 191 

Adelphocoris rapidus : 195 

Western twelve-spotted cucumber beetle: 114 

Belted cucumber beetle : 115 

Melon aphis : 135 

Garden springtail : 139 

Potato aphis : 150 

Common stalk-borer : 157 

Grape colaspis : G7 

Bean thrips : 69 

Bean aphis : 76 

Garden flea-hopper : 77 

Spotted cutworm : 262 

Greasy cutworm : 265 

Red-backed cutworm : 267 

Dark-sided cutworm : 268 



108 MANUAL OF VEGETABLE-GARDEN INSECTS 

Striped cutworm : 270 
Variegated cutworm : 276 
Yellow-headed cutworm : 281 
Spotted-legged cutworm : 282 
Clover cutworm : 284 
Army cutworm : 287 
Army-worm : 288 
Fall army-worm : 292 
Beet army-worm : 294 
Yellow-striped army-worm : 295 
Striped blister-beetle : 302 
Margined blister-beetle : 305 
Ash-gray blister-beetle : 300 
Black blister-beetle : 307 
Nuttall's bhster-beetle : 308 
Spotted blister-beetle : 309 
Two-spotted blister-beetle : 309 
Segmented black blister-beetle: 310 
Large black blister-beetle: 311 
Potato flea-beetle : 314 
Eggplant flea-beetle : 320 
Pale-striped flea-beetle : 321 
Red-headed flea-beetle : 323 
Smartweed flea-beetle : 323 
Western cabbage flea-beetle : 327 
Spinach flea-beetle : 329 
Yellow-necked flea-beetle : 331 
Three-spotted flea-beetle : 331 
Larger striped flea-beetle : 332 
Sweet potato flea-beetle : 332 
Hop flea-beetle : 335 
Root-knot nematode : 338 
Sugar-beet nematode : 342 
Millipedes: 342 



CHAPTER V 

INSECTS INJURIOUS TO CUCUMBER, SQUASH AND 

MELON 

Cucurbits are subject to attack by a large number of insects, 
the most important of which are : the cucumber beetles, the 
squash bugs, the squash-vine borer, the pickle worm, the 
melon worm and the melon aphis. Cutworms and flea-beetles 
also occasionally cause serious loss. The watermelon is singu- 
larly free from insect enemies but is sometimes seriously in- 
fected by the melon aphis. 

The Striped Cucumber Beetle 

Diabrotica viltata Fabricius 

This small, yellow, black-striped beetle is one of the most 
serious enemies of the cucumber, squash, melon and related 
plants. It is a native of America and is to be found in this 
country wherever its food plants are grown except in the far 
West. The greatest injury is to the young plants soon after 
they come up, by the beetles that have just emerged from 
hibernation ; the larvae also burrow in the stem both above 
and below the ground and often feed on the underside of the 
fruit when it lies on the soil ; the beetles sometimes destroy 
the flowers by eating off the pistils and the new brood of beetles 
in late summer causes considerable injury to ripening fruit by 
gnawing holes in the rind. 

109 



110 MANUAL OF VEGETABLE-GARDEN INSECTS 



The beetles hibernate under trash or, when such protection 
is not available, in the ground below the frost line. They 
emerge from hibernation in the spring from April to June, the 
exact date depending on the locality and the season. They 
usually appear before cucurbit plants are up and feed for some 
time on the pollen of flowers and on the leaves of certain plants, 
apple, horse-chestnut, wild thorn, elm, syringa, juneberry and 
many others. The beetles, hungry after their long winter's 
fast, congregate on squash and cucumber plants just as they 
are coming up and feed on the tender leaves and gnaw holes 

in the stems often just at the sur- 
face of the ground. Many plants 
are killed outright while others are 
so injured that they make only a 
sickly growth. Okra is sometimes 
attacked. 

The beetle (Fig. 68) is from -j^ to 
^ inch in length ; the head is black ; 
the thorax yellow and the wing- 
covers yellow with three longitudinal 
black stripes, the lateral pair not ex- 
tending to the tip. After feeding 
for some time, the beetles mate and 
the female begins egg-laying. Oviposition has been found to 
begin in Kentucky about the middle of June, on Long Island, 
New York, towards the last of June and in New Hampshire, 
about the first of July. Oviposition continues for about a 
month. Each female is capable of laying from seventy-five to 
one hundred eggs. The egg is about -^^ inch long, -^o^ inch wide, 
oval or elliptical in outline and light yellow in color. Some of 
the eggs are deposited in crevices in the ground but many are 
dropped by the female wherever she happens to be feeding. 
Eggs are sometimes found caught in the hairs of the leaves at 
the tip of the vines. The eggs hatch in a week or more and the 




Fig 



68. — The striped cucum- 
ber beetle (X 5^). 




INJURIOUS TO CUCUMBER, SQUASH AND MELON HI 

\ar\x work their way down alone; the stem or under the vines 
or fruit where they lie on the <;round. They burrow into the 
tissue, eausing more injury in this stage than is usually thought. 
Squash vines have been observed praetieally killed in July and 
early August from the attaeks of the grubs. The stem just 
below the ground is completely riddled by their burrows. The 
larva becomes mature in about a month. It is then about ys 
inch in length and very slender ; the color is white with the 
head, thoracic and anal plates brown (Fig. 69). When mature, 
the larva constructs an earthen cell a few inches below the sur- 
face within which it soon transforms to a nearly white pupa. 
The pupal stage lasts a 
week or more. The 
beetles begin to emerge 
the last of August or in ^',^ ^, . , , , , , " 

. '^ Fig. G9. — Striped cucumber beetle, larva 

September m the more (X7^). 

northern part of the 

insect's range and after feeding for some time on f.owers, 
such as goldenrod and asters, go into hibernation with the 
occurrence of heavy frost. Late in the season the beetles 
sometimes injure melons by eating holes in the rind and have 
been know^n to eat holes in bean pods. In the North there is 
only one generation annually ; in the South it is thought that 
the insect is double-brooded. 

The beetles also serve as carriers for a serious disease of 
cucurbits known as bacterial wilt. They not only transmit 
the disease from plant to plant in the summer, but the hiber- 
nating beetles carry over the wilt bacteria and infect the plants 
in the spring. 

Control. 

As a rule, attempts to poison the beetles have not been suc- 
cessful l^ecause the insects refuse to eat leaves covered with 
the poison. In many cases it is practicable to protect the 



112 MANUAL OF VEGETABLE-GARDEN INSECTS 

young plants by covering them with some kind of screen. 
Cheesecloth, mosquito-netting and wire screen are often used 
for this purpose. Various methods are followed to hold the 
covering in place over the plants ; sometimes a shallow wooden 
box is used, open at top and bottom and the screen is tacked 
over the top ; sometimes a barrel hoop is cut into halves, the 
two parts crossed at right angles and the ends stuck in the 
ground ; the screen is placed over the hoops and earth thrown 
on the edges to hold it down; sometimes the cover is made 
entirely of wire screen in the form of a cone and one grower 
successfully used wire pie-covers. The difficulty in using covers 
is that they have to be removed before the plants become very 
large and if the beetles are very abundant injury may follow. 

Much may be accomplished to prevent injury by keeping 
the plants thoroughly covered with bordeaux mixture or arse- 
nate of lead (paste), 3 pounds in 50 gallons of water. This 
renders the plants distasteful to the beetles and is especially 
valuable on cucumbers if used in connection with trap crops. 
Squashes are often more attractive to the beetles than cucum- 
bers and have been used successfully for trap crops. When it 
is desired to protect a field of cucumbers, a few rows of squashes 
should be placed around the field about a week before planting 
the cucumbers ; another planting of squashes should be made 
at the time the main field is set and if the beetles are abundant, 
more squashes should be planted about a week later. The 
beetles will collect on the squash plants, where it is sometimes 
possible to poison some when they first arrive and before they 
have had a chance to feed on unpoisoned foliage. Only a part 
of the trap crop should be sprayed or dusted with the poison 
for fear of driving the beetles to the cucumbers. Whenever a 
trap crop is used, it is important to keep the main crop well 
sprayed with bordeaux mixture or arsenate of lead. Experi- 
ments in New Hampshire have shown that arsenate of lead is 
just as effective as a deterrent for the beetles as bordeaux 



INJURIOUS TO CUCUMBER, SQUASH AND MELON 113 

inixtiiiT and that it does not {'hock the growtli of the plants if 
appHed while they are small as does the latter. Tohaeeo dust, 
air-slaked lime and land plaster are of value as deterrents and 
will be found useful in the home garden. 

Much loss from beetle attack may be prevented by thorough 
cultivation and the use of the proper fertilizers to stimulate 
rapid growth. At the end of the season, all rubbish, including 
the old vines, should be collected and burned in order fo reduce 
to a minimum the shelter for the hibernating beetles. 

References 

N. Y. (Geneva) Agr. Exp. Sta. Bull. 158. 1899. 

Ky. Agr. Exp. Sta. Bull. 91, pp. 1-15. 1901. 

U. S. Bur. Ent. Cire. 31. 1898 and 1909. 

N. H. Agr. Exp. Sta. 19tli and 20tli Kept., pp. 499-513. 1908. 

Western Cucumber Beetle 

Diabrotica trivittata Mannerheim 

On the Pacific Coast the striped cucumber beetle is replaced 
by a closely related form. This species may be distinguished 
from its eastern relative by its darker color and by having the 
antennte and the greater part of the legs black. The habits 
and life history of the western form are very similar to those 
of the eastern species but it has not on the whole proved as 
injurious. There are said to be two generations annually. 
When attacking cucurbits, it may be controlled by the same 
means as suggested for that species. 

The Twelve-Spotted Cucumber Beetle 

Diabrotica duodecempunctata Olivier 

This beetle is also known as the southern corn root-worm 
and is discussed on page 222 as a corn pest. When attacking 



114 MANUAL OF VEGETABLE-GARDEN INSECTS 

cucurbits, it may be controlled by the measures suggested for 
the striped cucumber beetle. 



The Western Twelve-Spotted Cucumber Beetle 

Diabrotica soror Leconte 

On the Pacific Coast the southern corn root-worm (page 222) 
is replaced by a closely related species which may be distin- 
guished by having the entire underside of the body and the legs 

black ; the antennae are only 
slightly paler at the base. The 
two posterior spots on the wing- 
covers have a tendency to 
coalesce (Fig. 70). 

The beetles attack cantaloupe, 
watermelon, squash and cucum- 
ber plants just as they are com- 
ing up and also eat holes in the 
fruit. They are also destructive 
to beet, spinach, bean, pea, cab- 
bage, turnip, potato, lettuce, 
mustard, peanut, corn, alfalfa 
and clover. They are especially troublesome on farms on 
which flowers are grown for seed. They sometimes defoliate 
young deciduous and citrus trees and cause considerable injury 
by eating holes in the fruit of the peach, prune and apricot. 
The beetles hibernate in sheltered places, emerging in early 
spring. After feeding for about eighteen to twenty-four days, 
the small, dirty white, oval eggs are deposited singly or in 
clusters of four or five to fifty in the ground near the base of 
the food plant, about one quarter to one half inch from the 
surface. The eggs are deposited over a period of about three 
weeks. They hatch in nine to twenty-six days with an aver- 
ao;e of about two weeks. The larvae have been found feeding 




Fig. 70. — The western twelve- 
spotted cucumber beetle ( X 5). 



INJURIOUS TO CUCUMBER, SQUASH AND MELON 115 

on the roots of pea, alfalfa, peanut and beet and are said to 
mine into the stems and rinds of melons, cucumber and squash 
where they touch the ground. The larvfe become mature in 
five weeks to two months, those hatching first requiring the 
longer period. The full-grown grub is a little less than ^ inch 
in length, elongate, cylindrical, white or yellowish in color, 
with the head, thoracic shield and anal plate brown. The 
lar\'{e pupate in earthen cells in the ground and in about two 
weeks the beetles emerge. In Oregon the beetles of the new 
brood become abundant in early July ; in California somewhat 
earlier. 

The western twelve-spotted cucumber beetle can be con- 
trolled by the same measures as recommended for the striped 
cucumber beetle. 

The Belted Cucumber Beetle 



Diabrotica halteata Leeonte 

In the lower Rio Grande Valley in Texas truck cro})s are 
often subject to attack by the belted cucumber beetle. This 
beetle is about ^ inch in length, 
tTie head red and the prothorax 
and wing-covers bluish green, each 
of the latter marked with two spots 
in front, two transverse bands and 
a spot near the apex which are yel- 
lowish. The femora are greenish, 
the remainder of the legs blackish 
(Fig. 71). The beetles feed on 
pea, bean, potato, pepper, turnip, 
peanut, squash, cantaloupe, cucum- 
ber, watermelon, pumpkin, okra, 
spinach, beet, lettuce, onion, asparagus, corn, cotton, alfalfa, 
cowpea and other leguminous crops. They seriously injure 




Fig. 71. 



— The beltetl cucumber 
beetle (X 5|). 



116 MANUAL OF VEGETABLE-GARDEN INSECTS 

eggplant, tomato and cucurbits by destroying the foliage and 
by feeding on the blossoms and blossom buds. 

The adults are active during the winter but do not lay eggs 
until March. The egg is oval, pale yellow in color and about 
4V inch in length. The eggs are laid in the ground near the 
base of the food plant singly or in clusters of four or five. 
They hatch in nine to eleven days. The larvae have been 
found feeding on the roots of corn, sorghum and beans. The 
larva becomes mature in about twenty-five days. It is nearly 
^ inch in length, light yellow in color with the head and anal 
plate brownish. The light yellow pupre, about ^ inch in 
length, are found in small earthen cells two or three inches 
below the surface. About eleven days are spent in the pupal 
stage. In the second generation the time required for the 
insect to pass through its different stages is somewhat shorter ; 
viz., egg stage five days, larval stage fourteen days and pupal 
stage five days. 

Experiments in Texas have shown that truck crops may be 
protected from the attacks of this beetle by spraying with 
arsenate of lead (paste), G to 10 pounds in 100 gallons of water 
or bordeaux mixture. 

Two other closely related cucumber beetles, Diabroiica con- 
nexa Leconte and Z). pidicornis Horn, occur in Texas and 
sometimes attack cucurbits and beans. The latter species 
deposits its eggs on the under surface of cucumber leaves. 

Reference 
U. S. Bur. Ent. Bull. 82, pp. 76-82. 1910. 

The Squash Bug 

Anasa trislis DeGeer 

Throughout the whole United States, cucurbits are subject 
to the attacks of a large brownish bug that has a highly offen- 



INJURIOUS TO CUCUMBER, SQUASH AND MELON 117 






sive odor, licnce the name stink-})ug by which it is known in 
many loeahties. The insect ranges from Canada to Central 
America. Its favorite food phmts are squash and pumpkin, 
but melons and cucumbers are sometimes severely injured. 
As a rule the squash bug is more destructive in the small garden 
than in the fields of the commercial grower. The reason is 
that in the case of large tilled fields the quantity of hibernating 
shelter is relatively smaller, and as the insects are distributed 
over a larger area the injury is not so great to any particular 
])lant. In the home garden the 
squash bug is a most troublesome 
and vexatious pest. 

The adult bugs hibernate in 
rubbish, in board-piles or under 
any convenient shelter. They 
emerge from winter quarters 
rather late in the spring and are 
often found about gardens resting 
under pieces of boards or other 
shelter, apparently waiting for the 
squashes to come up. The adult 
bug (Fig. 72) is about f inch in 
length and of a dirty brownish 
black color above and brown 

mottled wath black below. The old bugs attack the plants 
as soon as they are well out of the ground and often kill them 
outright. In feeding, the insect punctures the plant with 
the bristles of its beak and sucks out the sap. At the same 
time it apparently injects into the wound some injurious 
poison. When the plants are small, a few punctures are 
enough to cause serious injury. After mating, the female 
deposits her eggs in clusters of three or four to fifty or more 
usually on the under surface of the leaves. The arrangement 
of the eggs varies greatly ; usually they are placed in more or 




Fi( 



I. — The sciua.sh hug, 
adult (X 21). 




118 MANUAL OF VEGETABLE-GARDEN INSECTS 

less regular rows, sometimes crowded closely together but more 
often rather widely separated. The egg (Fig. 73) is about 
YY inch in length and flattened on three sides ; the side next 
to the leaf is somewhat concave. When first laid it is whitish, 
but soon turns to a yellowish brown and gradually becomes 
darker as the time for hatching approaches. 

The eggs hatch in six to fifteen days. The young bug leaves 
the egg through an opening at one end made by pushing out a 
small circular disk-like piece of the shell. The newly hatched 
nymph is gayly colored ; the body is green, the legs, antennje 
and beak rose color and the head and the front part of the 
thorax another shade of rose. After a 
few hours the rose color changes to 
black. In the course of its development, 
the insect passes through five nymphal 
stages, molting its skin five times and 

Ficj. 73. — Eggs of the ''.'. .^ in^i i xe 

squash bug (X li). acqunung wmgs at the fifth molt. Alter 
the first molt, the color of the nymphs 
is a pruinose gray, almost white. Four or five weeks are 
passed in the nymphal stage. The young nymphs hatching 
from a cluster of eggs remain together for some time 
feeding on the underside of the leaf. After the first molt, 
they move about more freely. When not feeding, the older 
nymphs and the adults often congregate around the base of 
the plant or hide under lumps of earth. The feeding of the 
nymphs causes the injured leaves to wilt, curl up, turn brown 
and die. Sometimes the bugs kill the plant outright but more 
often they merely injure it so that growth is checked and the 
vine is unable to mature a full crop of fruit. The nymphs 
begin to reach maturity- in August but it often happens that 
frost kills the vines while many of the bugs are still immature. 
In such cases they often congregate on the unripe fruits, from 
which they are able to extract enough food to complete their 
growth. There is only one generation annually. 



I 



IXJURIOUS TO CUCUMBER, SQUASH AND MELON 119 

Control. 

The adult squash bug is very resistant to contact sprays 
and recourse must be had to other methods of controh The 
number of bugs appearing on the plants in the spring can be 
greatly decreased by practicing clean farming and thus reduc- 
ing the available shelter for the hibernating insects. After the 
croj) is harvested, the vines should be raked up and either 
burned or converted into compost. This will prevent many 
of the later hatched nymphs from reaching maturity. The 
use of proper fertilizers and thorough cultivation will often 
enable the vines to withstand attack and outgrow the injury. 
After the ground has been fitted but before the plants are up, 
many of the bugs can be trapped under pieces of boards placed 
on the ground. They collect under such shelter during the 
night. The boards should be examined every morning and the 
insects killed by hand. It will also pay to keep watch of 
the plants for some time after they come up and hand-pick all 
the bugs found on them. All egg-masses should be destroyed 
by scraping them off with a knife or by crushing. When the 
nymphs are found, they too may be hand-picked or killed by 
spraying with "Black Leaf 40" tobacco extract, 1 part in 400 
])arts of water in which enough soap has been dissolved to 
make a good suds. An upturned nozzle will be found con- 
\'enient for reaching the young bugs on the underside of the 

leaves. 

References 

U. S. Div. Ent. Bull. 19, pp. 20-28. 1899. 
U. S. Div. Ent. Circ. 39. 1899 and 1908. 
N. H. Agr. Exp. Sta. Bull. 89. 1902. 

The Horned Squ.\sh Bug 

Anasa armigera Say 

The horned squash bug is frequently associated with the 
{)receding species, from Missouri to Maryland and southward. 



120 MANUAL OF VEGETABLE-GARDEN INSECTS 

The two species are very similar in general appearance but the 
horned squash bug may be distinguished from the common 
form by the prominent angles of the thorax, by the row of four 
white spots on each side of the upper surface of the abdomen 
and by the spine near the tip of each femur. There is also an 
acute horn just in front of each eye (Fig. 74). The nymphs 
are easily distinguished. In the earlier stages A. armigera has 
the legs banded with red or brown and the next to the last seg- 
ment of the antennte is widened ; in .1. tristis the legs are nearly 
uniform black and the antennal segments 
are of nearly the same width ; in the 
later stages the sides of the thorax are 
strongly dentate in .1. armigera, smooth in 
.1. tristis. The life history and habits of 
the two species are nearly alike. The 
horned squash bug may be controlled by 
the same measures as are suggested for 
the common squash bug. 

In the South from Florida to Louisiana 
and New Mexico, another species, Anasa 
andrewsi Guerin-Meneville, closely related 
to the common squash bug, has recently 
been "reported as injurious to cucurbits. The adult of this 
species is more slender and of a lighter color than the common 
form but the insect does not differ greatly in life history, 
habits or the nature of the injury inflicted. The egg and 
early stages have not been described in detail. 

This subtropical squash bug may be controlled by the 
measures recommended for its northern relatives. 



1 




Fig. 71. — The horned 
squash bug ( X 2). 



Reference 
U. S. Div. Ent. Bull. 19, pp. 28-34. 1899. 



INJURIOUS TO CUCUMBER, SQUASH AND MELON 121 



The Melon Leaf-Bug 

Pycnode es quadnmaculatus Guerin-Meneville 

This leaf-bug has been reported as seriously injuring melons, 
squashes and beans in Arizona. The adult bug is about ^ 
inch in length, black, mottled with gray and whitish. The 
legs are pale yellow with the outer two fifths of the hind femora 
black. The life history has not been recorded. The injury is 
caused by the feeding punctures of the insects. The adults 
are very active and difficult to hit with a spray. No satis- 
factory method of control has been devised. 



The Southern Leaf-Footed Plant-Bug 

Leptoglossus phyllopus Linnaeus 

In the southern states, tomato, eggplant, melon, potato and 
artichoke are often injured by the feeding punctures of a 
chocolate-brown bug closely related to the 
squash bug. This insect is also well 
known to fruit-growers from its habit of 
puncturing oranges, peaches, plums and 
pears, causing them to decay. The adult 
(Fig. 75) is between ^ and f inch in 
length. The hind tibiae are flattened and 
greatly expanded. The edge of the ex- 
panded portion is notched and toothed 
and flecked with yellowish white so as to 
resemble a bit of dried leaf 
are crossed near the middle by a yellowish 
white baud. The adults hibernate and 
in the si)riiig may be found in abundance on the yellow 
thistle, where they deposit their eggs end to end in a row 
along a stem or the midrib of a leaf. The egg is golden 




The wings Fig. 75. — The southern 
leaf-footed plant-bug 
(X H). 



122 MANUAL OF V ECETABLE-dAllDEN INSECTS 

brown, cylindrical and flattened at each end and on the side 
of attachment. The eggs hatch in a few days and the young 
nymphs may be found sucking the juices from the plant. 
The nymphs are more reddish than the adults and do not 
acquire the leaf-like expansion on the hind legs until nearly 
mature. They become full-grown in about three weeks, pass- 
ing through five stages in the course of their development. 

Most of the injury to cultivated plants is inflicted by the 
adults, the nymphs being usually found only on yellow thistle. 
They puncture the stems of cucumber, melon and asparagus, 
causing them to wilt and die. The tender growing tips of 
tomato, potato, pea and bean are injured in a similar way and 
the bugs sometimes attack the fruit of tomato. In Louisiana 
the insect has been reported as a serious pest of the globe arti- 
choke. The bugs also puncture the bolls of cotton and are 
injurious to pepper. 

Control. 

In the small garden, hand-picking the bugs in the UK^rning 
while they are sluggish is probably the most practical method 
of controlling the pest. Since the insect breeds largely on the 
yellow thistle, this weed should not be allowed to grow in 
abundance in the vicinity of susceptible crops. In some cases 
it might be advisable to leave a few thistles as a trap crop on 
which the adults will congregate and where they may be 
destroyed. 

The Northern Leaf-Footed Plant-Bug 

Leptoglossus oppositus Say 

From New Jersey to Indiana, Missouri, Oklahoma and 
southward, squash, cucumber, melon and tomato are occa- 
sionally attacked by a leaf-footed plant-bug closely related to 
the species last treated. The northern form is slightly larger 



INJURIOUS TO CUCUMBER, SQUASH AND MELON 123 

and stouter and the band across the front wings is represented 
by two small whitish spots. The wald food plants of the insect 
have not been accurately determined. The bugs often punc- 
ture the fruit of peach, plum, cherry, pear, tomato and cucum- 
ber and sometimes attack cotton bolls. They also feed on 
tlie stems of cucumber, squash, cantaloupe, watermelon and 
tomato, causing the vines to wilt and die. 

The insect hibernates in the adult stage but the bugs do not 
appear in the field until late in the season, about the first of 
July at Washington. The egg is bronze-brown, about yg inch 
in length, cylindrical and flattened at each end. The eggs are 
laid end to end in rod-like row's of six to twenty-six, attached 
to the stems or along the veins of the leaves. The eggs hatch 
in about a week and the young nymph leaves the egg-shell by 
forcing out a circular lid on the side near the end of the egg. 
The newly hatched nymph is coral-red in color with the legs 
nearly black. The basal half of the antennse is black and the 
outer half red. The insect passes through five nymphal 
stages and becomes adult in twenty-five days to about a month 
after hatching. There is only one generation annually so far 
as known. 

Control. 

The nymphs can be killed with "Black Leaf 40" tobacco 
extract, 1 part in 500 parts of water to which enough soap has 
been added to make a suds. Kerosene emulsion and strong 
soap solutions have also been suggested for the control of this 
pest. In the garden the adults may be hand-picked in 
the cool of the morning while they are sluggish. 



References 

U. S. Div. Ent. Bull. 33, pp. 18-25. 1902. 

Forbes, 23rd Kept. Stato Ent. III., pp. 197-108. 190.5. 



124 MANUAL OF VEGETABLE-GARDEN INSECTS 

The Squash- Vine Borer 

Melittia satyriniformis Hiibner 

In many localities the squash-vine borer is the most injurious 
insect enemy of the squash and pumpkin. It also attacks 
cucumber and melon. It is most destructive to late squashes, 
such as Hubbard and INIarrowfat. The insect ranges from 
Canada, through the states east of the Rocky IVIountains south- 
ward into South America. 

The moths appear in the fields as early as April or May in 
Georgia and North Carolina, in early June in New Jersey and 
a little later in Connecticut, or at about the time that early 
cucurbits have come up. The moth has an expanse of 1 to 1-j 
inches ; the front wings are opaque, nearly black in color with 
metallic greenish reflections in certain lights ; the hind wings 
are transparent and scales are present only along the margin 
and on the veins. The abdomen is marked with red or orange ; 
the hind legs are long and ornamented with tufts of long orange, 
black and white hairs. The moths fly in the heat of the day 
and when on the wing are often mistaken for wasps. In the 
evening they may be seen resting on the leaves of the vines 
and are then easily caught. The female moth deposits her 
eggs on the stem of the vine near the base, while the plants are 
small and later at almost any point. The egg is about ^ inch 
in length, dull red in color, oval in outline, flattened on the side 
of attachment and has an impressed area on the upper side. 
The shell is very brittle. Each moth is capable of laying over 
two hundred eggs, but the average number is probably some- 
what less. The eggs hatch in six to fifteen days. The young 
caterpillar soon enters the vine and then burrows through the 
stem, preferably towards the root but often in the opposite 
direction. Later in the season the larvje may be found in all 
parts of the Stem and even in the leaf petioles and in the fruit. 



INJURIOUS TO CUCUMBER, SQUASH AND MELON 125 

The young caterpillar differs from the later stages in having 
the head larger in proportion to the body, in being more hairy 
and in having the body more tapering behind. When full- 
grown, the caterpillar (Fig. 76) is about an inch in length ; the 
body is white and the head dark brown with an inverted V- 
shaped white mark. The burrows occupied by the larger larvre 
are usually wet, slimy and partly filled with excrement ; decay 
often ensues and hastens the death of the vine. The greater 
part of the excrement, however, is thrown out of the burrow 




Fig. 76. — The squash-vine borer (X Ij). 

through holes in the stem. These coarse, yellowish grains of 
frass collect on the ground under the vine and are usually the 
first indication that the plant is infested. The caterpillars 
reach maturity in about four weeks in the latitude of New 
Jersey. When mature the caterpillar leaves the stem, enters 
the ground one or two inches and there constructs a tough 
silken brownish or blackish cocoon into the outer layers of 
which particles of dirt are incorporated. The cocoon is about 
f inch in length. After making the cocoons, some of the cater- 
])illars soon transform to puppe, while the others remain in the 
larval condition until the following spring. Those that pupate 
soon after spinning the cocoon usually transform to moths 



126 MANUAL OF VEGETABLE-GARDEN INSECTS 

the same season. The dark brown pupa is about f inch in 
length ; its head is armed with a sharp horn-hke process by 
means of which it cuts its way out of the cocoon. After leav- 
ing the cocoon, the pupa works itself up to the surface of the 
ground in order to permit the escape of the moth. In the 
Gulf states the insect has normally two broods ; in the latitude 
of Washington the second brood is only partial while farther 
north, in New Jersey and on Long Island, the second brood is 
much smaller, and still farther north there is only one genera- 
tion annually. 

Control. 

The squash-vine borer cannot be controlled by applications 
of insecticides, but it may be held in check by practicing such 
of the following methods as are warranted by the severity of 
the outbreak or by other local conditions. As the insect passes 
the winter in the ground, it is not good policy to grow squashes 
in the same field year after year. If for any reason it is neces- 
sary to raise successive crops of squashes on the same ground, 
the land should be harrowed in the fall to expose the cocoons 
and then plowed deeply the following spring. In all cases the 
vines should be collected and destroyed as soon as the crop is 
harvested in order to prevent the late caterpillars from reaching 
maturity. If all the growers in a locality would co-operate in 
the early destruction of the vines, the number of moths appear- 
ing the following spring would be greatly reduced. In some 
cases much injury may be avoided by late planting in connection 
with heavy fertilization to promote rapid and heavy growth. 
In some localities the use of early squashes as a trap crop has 
been attended with success. A few early squashes, such as 
crooknecks, are planted early around the field and between the 
rows of the late varieties. The moths will deposit their eggs 
on the early squashes and the main crop, coming up later, will 
escape the greater part of the infestation. As soon as the 



INJURIOUS TO CUCUMBER, SQUASH AND MELON 127 

early sciuushcs are harvested, or sooner if they erowd the main 
crop, the vines should be pulled up and burned or composted 
in order to kill the borers they contain. After the borer has 
once entered the vine, there is nothing to be done but to cut it 
out with a knife. If care is taken to make the cut lengthwise 
of the stem and if the vine is immediately covered with earth 
at the injured point, the wound soon heals and the vine con- 
tinues its growth. Some growers make a practice of covering 
the stem with earth two or three feet from the base in order 
t ) make the vine throw out a new root system, which will 
sustain the plant in case the main stem is injured at the ba,se. 
In s:)me cases it would i)ay t;) keep a sharp lookout for the 
moths in the evening when they are resting on the vines. They 
are easily seen and are not difficult to capture. For every 
female killed before she has deposited her eggs, there will be 
from one to two hundred less eggs laid on the vines. 

References 

N. J. Agr. Exp. Sta. Bull. 94, pp. 27-40. 1S93. 
U. S. Div. Ent. Bull. 19, pp. 34-40. 1899. 
U. S. Farm. Bull. G()8. 1915. 



The Pickle Worm 

Diaphania 'tiilidulis StoU 

The pickle worm and its near relative the melon worm are a 
serious drawback to the profitable growing of cantaloupes, 
squashes and cucumbers throughout the southern states. In 
some years the former appears in destructive numbers as far 
north as New York and Michigan and the moths have been 
taken in Canada. The insect ranges southward through the 
West Indies into South America. As far as known, its food 
plants are all members of the gourd family : cantaloupe, cucum- 



128 MANUAL OF VEGETABLE-GARDEN INSECTS 



ber and squash. It has been reported as attacking the water- 
melon in Georgia ; the pumpkin is said to be immune. 

The pickle worm hibernates in the pu])al stage in a flimsy 
cocoon in a curled leaf of the food plant usually lying on the 
ground. The moths do not emerge until rather late ; the early 
part of June in Georgia and North Carolina. The moth (Fig. 
77) has an expanse of 1 to ^ inches ; the general color of the 
wings is yellowish brown with a purplish metallic reflection in 
certain lights; a large irregular spot on the front wing and 
the basal two thirds of the hind wings are semi-transparent 

yellow. In both sexes 
the tip of the abdomen 
is ornamented with a 
brush of long scales, 
larger in the male. The 
moths do not fly during 
the day or in the early 
part of the night ; they 
are active and deposit 
their eggs after mid- 
night and go into hid- 
ing at daylight. The 
egg is about ^V inch in length, much flattened and elliptical 
in outline. It is nearly white when first laid but soon 
becomes yellowish. The eggs are deposited singly or in 
masses of three to eight on the flowers, flower-buds or on 
the tender opening leaves at the end of the ^'ines. They are 
loosely attached to the plant-hairs and can be easily brushed 
off. They hatch in three or four days and the young cater- 
pillars soon burrow into the tender tissue of the blossom or 
bud. The greater number do not reach the fruit until after 
the first or second molt. On squash many complete their 
growth within the blossoms, but on cantaloupes and cucum- 
bers the caterpillars that are feeding in the blossom buds usually 




Fig. 77. — The pickle worm moth ( X 2). 



INJURIOUS TO CUCUMBER, SQUASH AND MELON 129 

migrate to the fruit when about half grown. Many of those 
that start feeding on the eluster of terminal buds burrow down 
into the stem and eomplete their growth there ; some are found 
in the leaf petioles. The vines are often riddled in this way 
but the greatest injury is caused by the burrows made in the 
fruit. On reaching the fruit, some of the caterpillars feed for- 
a time in the rind while others burrow directly to the center. 
While the caterpillar is near the surface, the excrement is thrown 
out of the opening ; later it is left in the burrow. The cater- 
pillars often leave one fruit and enter a second or third and 
may even migrate to another vine. In the case of cantaloupes 
and squashes, decay is almost certain to result whenever a 
caterpillar has gnawed through the rind, thus greatly increasing 
the loss. 

The newly hatched lar^'a is about Yt inch in length and 
yellowish white in color. After a shprt time a transverse row 
of brownish or blackish spots becomes apparent on each seg- 
ment. These spots become more distinct with successive molts 
and persist until the fourth, when they are lost. In the fifth 
and last stage the caterpillar is about finch in length, the head 
and thoracic shield are yellowish brown and the body is whitish, 
yellowish or greenish, depending on the nature of the food. 
Most of the caterpillars take on a dull coj)pery color above soon 
after the fourth molt. The caterpillar becomes mature in 
twehe to sixteen days after hatching. It then spins a loose 
silken cocoon, usually in a curled leaf, and after resting for 
about a day transforms into a pale green pupa, ^ to nearly f 
inch in length, which after a short time changes to brownish. 
The head of the pupa is bluntly pointed and the caudal end is 
acute and armed with a group of short hooked spines. In the 
summer the duration of the pupal stage is a week to ten days. 
The time required for the complete life cycle of the insect as 
determined in North Carolina \-aries from twenty-three to 
thirty-one days. In North Carolina there are four generations 



130 MANUAL OF VEGETABLE-GARDEN INSECTS 

annually with sometimes a partial fifth when the fall is warm. 
The first generation is always small in numbers and is usually 
entirely overlooked. In the second and third generations the 
caterpillars become very numerous and the loss is correspond- 
ingly great. Cantaloupes harvested before the appearance of 
the second brood of caterpillars usually escape injury, while 
those that mature later are often entirely destroyed. 

Control. 

Attempts to control the pickle worm by spraying with arseni- 
cals have been unsuccessful. The caterpillars feed very little 
in the open and, therefore, do not eat enough of the poison to 
be killed. The number of moths appearing the following season 
can be considerably lessened by collecting and destroying the 
vines as soon as the crop is harvested. The waste fruits and 
fallen leaves should be raked up and destroyed with the ^'ines 
either by burning or by turning them into compost. Early 
fall plowing of infested fields will also destroy a large propor- 
tion of the larvse and pupae. Rotation of crops and planting 
cucurbits at a distance from fields infested the previous season 
does not give as much relief as would be expected, because the 
moths are able to fly a considerable distance in search of plants 
on which to deposit their eggs. By planting the crop early, 
much injury may be avoided and this method should be adopted 
whenever practicable. 

In the case of cantaloupes, excellent results in protecting 
the crop have been obtained by planting squashes as traps 
throughout the field. Squash vines with their large and odor- 
ous flowers are more attractive to the moths than other cucur- 
bits. If enough squash vines are present in a field, the moths 
will deposit nearly all of their eggs on them and" the canta- 
loupes will escape. For this purpose the squashes should be 
planted at intervals of about two weeks so as to furnish an 
abundance of buds and blossoms during July and August. 



INJURIOUS TO CUCUMBER, SQUASH AND MELON 131 



The earlier squash vines should be removed and destroyed 
before many worms have reached maturity on them. The 
use of squashes as trap crops seems to be the most practicable 
way of preventing injury to cantaloupes in many parts of the 
South. 



References 

Ga. Agr. Exp. Sta. Bull. 54. 1901. 

N. C. Agr. Exp. Sta. Bull. 214, pp. 100-126. 



1911. 



The IMelon Worm 




DiUphania hyalinata Linnaeus 

The melon worm is occasionally found as far north as New 
York, southern Canada and Michigan but causes little or no 
injury north of North 
Carolina. In the south- 
ern states, it is a serious 
pest of cantaloupe, 
squash, cucumber and 
pumpkin and has been 
known to injure water- 
melon. 

The insect passes the 
winter as pupae in loose 
silken cocoons in the 
dead leaves or under the 
shelter of any con^Tnient rubbish. The moths do not emerge 
vmtil rather late in the season, in June or July in North 
Carolina. The moth (Fig. 78) has an expanse of less than 
an inch to 1^ inches. The wings are pearly white with a 
broad shining, iridescent brown band along the front and 
outer margins. The head and front part of the thorax 
are brown. The body is silvery white and the tip of 






Fig. 78. — The melon worm moth ( X 2). 



132 MANUAL OF VEGETABLE-GARDEN INSECTS 

the abdomen bears a conspicuous brush of elongate scales, 
yellowish at the base and white, brown or black at the tip. 
The eggs are laid on the buds, young leaves, stems and some- 
times on the main stalk of the vine, singly or in groups of two 
to six, sometimes overlapping. The egg is oval, about -^ inch 
in length, flattened and pearly white when first deposited but 
soon acquiring a yellowish tinge. The eggs hatch in three or 
four days in warm weather and the larvae begin feeding on the 
underside of the leaves or among the buds and sometimes bore 
into the latter. The newly hatched larva is about -^ inch in 
length, light straw-color with the head light brown. The two 
light stripes do not become apparent until after the first molt. 
In the second stage the color becomes yellowish or greenish 
from the ingested food. In the third stage the two white sub- 
dorsal stripes become more prominent and serve to distinguish 
the caterpillar from the pickle worm, in which they are not 
present. In the fifth and last stage the larva is f to l-j inches in 
length and mottled greenish yellow in color. Shortly before 
pupation, the larva contracts to about f inch in length and 
changes to a light yellow or straw-color, the white stripes hav- 
ing disappeared some days earlier. The caterpillars become 
mature in about two weeks and spin loose silken cocoons usually 
in a folded or rolled leaf in which they transform to brownish 
pupae about f inch in length. The moths emerge in a week or 
ten days. The life cycle requires a little less than a month in 
the summer in North Carolina. The first brood of caterpillars 
feeds to a considerable extent on the foliage and usually does 
not cause much injury to the fruit. The larvse of the later 
generations at first feed on the buds or foliage and do not attack 
the fruit until the third stage. On reaching the fruit, they may 
feed for some time on the surface but soon burrow through the 
rind causing decay. In North Carolina there are three genera- 
tions annually, the second, beginning the latter part of July, 
being the most destructive. 



INJURIOUS TO CUCUMBER, SQUASH AND MELON 133 

Control 

Cantaloupes and cucumbers may be protected from the melon 
worm by using summer squashes for a trap crop as recom- 
mended for the pickle worm. As the young caterpillars feed 
to a considerable extent on the foliage and on the surface of 
the fruit, many of them may be killed by spraying with arsenate 
of lead (paste), 3 pounds in 50 gallons of water. Usually the 
arsenate of lead can be applied to the greatest advantage in 
combination with bordeaux mixture as used for the control of 
fungous diseases. As soon as the crop is harvested, the vines 
and waste fruits should be gathered up and destroyefl. Deep 
plowing and a rotation of crops will also tend to hold the in- 
sect in check. 

Reference 
N. C. Agr. Exp. Sta. Bull. 214, pp. 12G-143. 1911. 

The Sqt^\sii Ladybird 

Epihichiia horealis Fabricius 

Nearly all the ladybird beetles are })eneficial to man, feed- 
ing, both as larvic and adults, on plant-lice, scale-insects and 
other small insects or on the eggs of larger ones. The squash 
ladybird, however, is an exception to the rule; both beetles 
and lar\'a^ feed on the leaves of squash, pumpkin, cantaloupe, 
watermelon and cucumber. The insect is a native of America 
and ranges through the United States east of the Rockies and 
southward to Argentina. Besides the plants just mentioned, 
it feeds on the prickly cucumber or wild balsam apple and on 
the one-seeded bur-cucumber. While capable of causing seri- 
ous injury to cucurbits, the insect is rarely abundant enough 
to become of economic importance. 

The squash ladybird hibernates in the adult condition in 
sheltered places, often in large colonies. The beetles emerge 



134 MANUAL OF VECET ABLE-GARDEN INSECTS 

about the middle of June in New Jersey. They are ^ inch in 
length, hemispherical in form and dull yellowish in color. 
The thorax has four small black spots and the wing-covers 
have twelve large spots arranged in three transverse rows 
(Fig. 79) . The yellow, elongate, subcylindrical eggs, xV ii^ch in 
length, are deposited in clusters of six to more than fifty. They 
hatch in about a week. The larva is yellow in color and armed 
with six rows of long branched spines ; when mature it meas- 
ures about f inch in length. The larvae feed generally on the 
underside of the leaves, eating off the surface in circular clearly 
defined areas. They become mature in 
about three weeks and then crawl to 
the upper surface of the leaf where 
they transform to pupse. The pupa is 
about ^ inch in length, yellow in color 
and covered with short simple black 
spines most abundant on the head, 
thorax and appendages. It is attached 
to the leaf by the posterior end of the 

^'^iadybh^d^CxT'^'''' ^^^y- "^^^ P^P^^ ^^^^^ ^^^^^ ^^^^ ^^^ 
to nine days. The beetles appear from 

the latter part of July throughout the remainder of the 

season. There is only one generation annually. 

Control. 

The squash ladybird is usually present only in small num- 
bers ; in such cases hand-picking will be the easiest and cheapest 
method of control. When more abundant, it would be better 
to spray the vines with arsenate of lead (paste), 2 to 2^ pounds 
in 50 gallons of water. 

Reference 
U. S. Div. Ent. Bull. 19, pp. 11-20. 1899. 




INJURIOUS TO CUCUMBER, SQUASH AND MELON 135 
The Melon Aphis 

Aphis gossypii Glover 

This insect is also known as the cucumber aphis, cantaloupe 
aphis, cotton aphis and orange aphis. When occurring in green- 
houses, it is known to gardeners as black aphis or black fly. 
It is widely distributed throughout the United States but has 
been reported as a serious enemy of cucurbits from Minnesota 
to Xew Jersey and southward. Its range extends to Brazil. 
It has attracted most attention in those localities where melons 
or cucumbers are grown on a large scale and in such cases the 
losses are often very great. It sometimes becomes of con- 
siderable importance as a cotton pest. The melon aphis has a 
wide range of wild food plants, including many common weeds 
and is occasionally found on a number of cultivated plants, 
such as spinach, okra, tomato, asparagus, eggplant, hop, 
morning-glory, bean and beet. 

The life history of the melon aphis has not been fully worked 
out and there is considerable difference of opinion as to how 
the insect passes the winter. It has been commonly supposed 
that winter eggs are produced in the fall and deposited on 
some food plant that will survive the winter. In fact eggs 
found on portulaca and strawberry have been described as 
belonging to this species. Great doubt has been cast on this 
view by the studies of Sanborn, who has shown that in Okla- 
homa the insect is unable to sur^•ive the winter in the open, 
and that each year it migrates northward from southern Texas, 
where it breeds continuously the year round. If it is true that 
the melon aphis does not winter over in the northern part 
of its range and that the infestation is annually renewed by 
migrants from the South, its habits in this respect are very 
similar to those of the famous green-bug of wheat, Toxoptera 
graminuin. 



136 MANUAL OF VEGETABLE-GARDEN INSECTS 



The date at which the melon aphis makes its first appear- 
ance on cucurbits varies considerably from year to year, but 
in the northern part of its range it is usually rather late in the 
season. Winged females fly or are blown into the field and, 
alighting on a vine, crawl to the underside of a leaf and begin 
feeding on the juices of the plant, which are extracted by means 
of the insect's beak. The female begins to give birth to living 
young at the rate of four or five each day and is soon surrounded 
by a numerous colony of young lice. When about six days old, 
these in turn reach maturity and begin to produce young. 
After remaining on one leaf two or three days, the female may 
move to another and found a new colony. The feeding of the 
lice causes the leaves to curl downward, turn brown, shrivel 
and die. When food becomes scarce, many of the wingless lice 
crawl to the tender leaves towards the end of the vine ; these 
in time succumb to the attack and the vine is finally killed or 
stunted so that the crop is small and of inferior quality. A 
large proportion of the lice of each generation acquire wings 
while the others remain wingless. The former fly to other 

vines and start new colonies 
of aphids. In this way the 
whole field soon becomes 
infested and unless the 
aphids are checked by the 
attacks of their numerous 
insect enemies or killed by 
artificial means, the crop is 
sure to be destroyed. 

The wingless female is 
about 2V ii^ch in length, varying in color from yellow to green 
or black, the eyes are brown and the cornicles black. In the 
winged female (Fig. 80) the head and the greater part of the 
thorax are black with the abdomen varying from yellow to 
dark green. Breeding continues until frost. Males and egg- 




FiG. 80. — Winged viviparous female 
melon aphis ( X 10). 



INJURIOUS TO CUCUMBER, SQUASH AND MELON 137 

producing females — the so-called true sexes — have not been 
observed. 

The melon aphis is held in check by the attacks of a large 
series of predaceous and parasitic insect enemies, most im- 
portant of which are several species of ladybird beetles, syrphus 
fly larvae, aphis lions and several species of parasites belonging 
to the family Braconidse. Under favorable weather conditions, 
these foes of the melon aphis are able to keep it so well under 
control that little or no damage is done. In cool, moist weather, 
however, following a backward spring, the activities of these 
beneficial insects are retarded and as the aphis is able to breed 
raj)idly under such conditions, the infestation becomes severe 
and it is not till late in the season that the enemies of the aphis 
r(>gain their supremacy. Many of these enemies feed on other 
kinds of aphids having difi'erent food plants and it has been 
suggested by Sanborn that it might be a useful practice to 
plant cabbage early around fields intended for cucurbits. 
The cabbage plants soon become infested with the cabbage 
aphis which furnish food for great numbers of predaceous and 
parasitic insects. At the first appearance of the melon aphis 
in the field, they will be on hand in sufficient abundance to 
hold the pest in check. 

Control. 

The melon aphis usually makes its appearance in a field on 
isolated vines scattered throughout the patch. It is important 
that a close watch should be kept in order to locate and destroy 
these first colonies. Growers sometimes pull up and bury the 
vines first attacked. Wliile the vines are small, it is possible 
to kill the aphids by fumigation with tobacco or carbon bisulfid. 
For this purpose portable covers are used made of oiled cloth 
stretched over a light wooden frame. The cover is placed 
over the vine and the tobacco fumes generated by l)urning 
strips of paper impregnated with nicotine. In case carbon 



138 MANUAL OF VEGETABLE-GARDEN INSECTS 

bisulfid is used, the liquid is placed in a shallow dish under the 
cover and allowed to evaporate. About a teaspoonful is suffi- 
cient for one cubic foot of space. The cover should be made to 
fit tightly to the ground to prevent the escape of the gas. The 
fumigation method is of most value when only a small number 
of vines are to be treated and when the aphids make their 
appearance before the vines have begun to run so as to cover 
much space. In large fields, spraying is more practicable and 
more likely to give satisfactory results. For successful spray- 
ing it is necessary that the vines be trained to run in the rows ; 
this also makes the cultivation easier. When the vines are 
trained in this way, it is not difficult to kill nearly all the 
aphids by using "Black Leaf 40" tobacco extract, f pint in 
100 gallons of water in which 5 or 6 pounds of soap have been 
dissolved. The spraying should be done as soon as the lice 
appear. A fine nozzle should be used, which, with good pres- 
sure, will produce a fine mist. It is important that the spray 
hit the underside of the leaves. This can be accomplished by 
using an upturned angle nozzle on a short extension rod. By 
doing careful and thorough work, it is possible to hit the under- 
side of practically every leaf. In case the infestation has be- 
come severe, it may sometimes be advisable to use a stronger 
solution of the tobacco extract, 1 pint of "Black Leaf 40" to 
100 gallons of water. Much stronger mixtures will not injure 
the foliage but are unnecessary and rather expensive. This 
method of fighting the melon aphis has proved practicable 
under commercial conditions. 



References 

Pergande, Insect Life, VII, pp. 309-315. 1895. 
Tex. Agr. Exp. Sta. Bull. 89, pp. 43-46. 1906. 
U. S. Bur. Ent. Circ. 80. 1906. 
Okla. Agr. Exp. Sta. Bull. 98. 1912. 
111. Agr. Exp. Sta. Bull. 174. 1914. 



INJURIOUS TO CUCUMBER, SQUASH AND MELON 139 
The Squash Aphis 

Macrosiphum cucurbikr. Middleton 

Squash and pumpkin are sometimes found infested by a 
green plant-louse about yV i'l^'b in length. The body of the 
winged form is green with the thorax tinged with brownish and 
the abdomen has a median line of darker green. In the wing- 
less form the body is green with few markings. This species 
has been reported as injurious in Connecticut, Ohio and Illi- 
nois and as infesting eggplant in Florida. Fortunately, it does 
not, as a rule, become abundant on the vines until late in the 
season when the crop is nearly matured. Its wild food plants 
include shepherd's purse, wild mustard and ground ivy. The 
aphids multiply parthenogenetically throughout the summer, 
both winged and wingless females being present. Males and 
egg-laying females are produced only in the fall. The ovip- 
arous female is wingless with the body green. The antennte, 
except the first two joints, and the tip of the cornicles are 
black. The males are smaller than the females with the body 
black and the margin of the abdomen greenish. The antennae 
are black, dark brown at the base. The winter is passed in the 
egg stage. 

The squash aphis can be controlled by the measures sug- 
gested for the melon aphis. 

The Garden Springtail 
Sminthurus hortensis Fitch 

Many garden plants are subject to injury soon after they 
come up by a minute wingless insect that eats out very small 
holes in the epidermis of the leaves and enlarges the wounds 
made by other insects. The insect is about ^ inch in length, 
dark purple in color spotted with pale yellow. The head is 



140 MANUAL OF VEGETABLE-GARDEN INSECTS 

large, separated by a narrow neck from the nearly globular 
united thorax and abdomen. At the tip of the latter there is 
a forked, tail-like appendage which when at rest is held close 
to the underside of the body and by means of which the insect 
is able to throw itself into the air. This habit has suggested 
the name of garden flea for these insects. 

The garden springtail has a wide range, having been reported 
from the northern United States, Europe, Japan and subant- 
arctic America. It has been reported as injurious in Maine, 
Massachusetts, New York, Indiana and Virginia. It attacks 
cucumber, squash, watermelon, cantaloupe, lettuce, bean, 
pea, cabbage, radish, turnip, kale, onion, beet, spinach, carrot, 
potato, tomato and tobacco and has also been found infesting 
wheat, rye and clover. The insects appear in great numbers 
just as the plants are coming up and so injure the leaves as 
either to stunt or kill the seedlings. The insects disappear in 
two or three weeks, practically all of the injury being done by 
the time the second or third true leaves appear. The life history 
of this springtail does not appear to have been worked out. 

Injury to seedlings by springtails may be prevented by dust- 
ing them with tobacco dust or air-slaked lime when they first 
come up and again in about a week if the insects are still present. 
The plants may be assisted to outgrow the injury by the appli- 
cation of a quick-acting fertilizer and by thorough early culti- 
vation. 

Reference 

Fitch, 8th Rept. State Ent. N. Y. for 1863, pp. 186-191 in 7th to 9th 
Repts. 1865. 

Other Cucumber, Squash and Melon Insects 

Corn ear-worm : 211 
Southern corn root-worm : 222 
Western corn root-worm : 225 
Stink-bugs: 232 
Garden webworm : 18 



INJURIOUS TO CUCUMBER, HQUASH AND MELON 141 

Serpentine leaf-miner : 46 
Yellow bear caterpillar : 357 
Tarnished plant-bug : 192 
Sugar-beet webworm : 97 
Spinach aphis : 105 
Grape colaspis : 67 
Garden flea-hopper : 77 
Well-marked cutworm : 263 
Greasy cutworm : 265 
Striped cutworm : 270 
Dingy cutworm : 271 
Variegated cutworm : 276 
Spotted-legged cutworm : 282 
Army-worm : 288 
F^all army-worm : 292 
Yellow-striped army-worm : 295 
Striped blister-beetle : 302 
Margined blister-beetle : 305 
Potato flea-beetle : 314 
Tobacco flea-beetle : 319 
Pale-striped flea-beetle : 321 
Larger striped flea-beetle : 332 
Hop flea-beetle : 335 
Root-knot nematode : 338 
Millipedes: 342 
Wheat wireworm : 348 
Red-spider : 351 
Corn and cotton wireworm : 349 



CHAPTER VI 
POTATO INSECTS 

The potato plant is a native of America and the insects 
affecting it are, with few exceptions, indigenous to the New 
World. In the East the most important potato insects are 
the Colorado potato beetle and the potato flea-beetle. The 
latter is treated on page 314. In California the potato tuber 
moth has in some localities threatened the potato-growing 
industry. Potatoes are especially subject to attack by blister- 
beetles. These pests are discussed in Chapter XVI. 

The Colorado Potato Beetle 

Leptinotarsa decemlineata Say 

The genus to which the Colorado potato beetle belongs 
occurs in greatest abundance in southern Mexico and Central 
America and it is supposed that this species originated in that 
region where it is now represented by closely related forms. 
It had, however, migrated northward so that by the early 
part of the last century it occupied a strip on the eastern slope 
of the Rocky INIountains from Texas and New Mexico north- 
ward to the Canadian boundary. The potato beetle was first 
described by Thomas Say in 1824 from specimens collected 
in the upper Missouri River Valley. The original food plant 
of the insect was the buffalo bur, Solarium rostratum. When 
the early settlers first began to plant potatoes in western 

142 



POTATO INSECTS 143 

Nebraska, the beetles discovered in this new plant a food 
greatly to their liking. In 1859 the beetles were feeding on 
potato about one hundred miles west of Omaha in Nebraska. 
This marks the beginning of the rapid and destructive eastern 
spread of the species. The Missouri River was crossed about 
1861 and the Mississippi by 1864. The main line of advance 
continued around the south shore of Lake Michigan, across 
Illinois, Indiana and Ohio, down through the natural highway 
of the lower Great Lakes through Ontario to the Province of 
Quebec and through Pennsylvania and New York and into 
New England. The Atlantic Coast was reached in 1874. 
In the early part of this great migration, the beetles averaged 
less than fifty miles a year, but after crossing the Mississippi 
River the yearly advance was considerably greater and the 
whole distance was covered at an average rate of about eighty- 
eight miles a year. 

It is now difficult to realize the apprehension with which 
the farmers viewed the coming of the potato beetle. Spray- 
ing was then unknown and arsenical poisons had not yet been 
used for the control of injurious insects. Although the value 
of paris green for the destruction of this pest was demonstrated 
in 1869, suitable apparatus for its application was not to be 
obtained. The first dusting and spraying machines were 
crude, clumsy and generally inefficient. If one considers the 
enormous hordes in which the beetles appeared and the com- 
pleteness with which they defoliated the plants in the newly 
infested areas, some idea can be gained of the serious situation 
that confronted the potato-growers of this period. 

In the newly occupied territory the beetles found few of 
their natural enemies and, therefore, for a time multiplied 
unchecked. In their eastward advance they moved through 
a region which was thickly settled, where their food was grown 
in great abundance and in a climate to which they easily 
adapted themselves. They were aided in their rapid advance 



144 MANUAL OF VEGETABLE-GARDEN INSECTS 

by the prevailing west and southwest winds during the season 
when the beetles were on the wing. The rapid spread of the 
Colorado potato beetle across the eastern United States has 
had no equal in historic times, except possibly in the case of 




Fig. 81. — Eggplant killed by the Colorado potato beetle. 

the recent advance of the cotton boll-weevil through the cotton 
belt of the southern states. 

After reaching the Atlantic Coast in 1874, the potato beetle 
gradually extended its range southward east of the Appa- 
lachian Mountains, but northern Florida was not invaded 
until about 1900. The advance down the Mississippi Valley 



POTATO INSECTS 145 

had also been slow and the beetles did not appear in central 
Louisiana until al)out the same date. The potato beetle is 
now generally distributed east of the Rocky Mountains from 
Montana to New Brunswick and Nova Scotia and southward 
to northern Florida. It also occurs in New ^Mexico and Ari- 
zona and in Idaho, Washington and Alberta. Where the 
potato is not available for food, the beetles will sometimes 
attack eggplant (Fig. 81), tomato, pepper and even tobacco. 
Ground cherry, thorn apple, henbane, Jamestown weed, horse 
nettle, belladonna and petunia also serve to carry the beetles 
through periods of scarcity. 

The potato beetle hibernates as an adult sometimes under 
rubbish but more frequently in the soil at a depth of several 
inches. The beetles emerge 




from their winter quarters in 
the spring just before early 
planted potatoes come up. 
At this time they will feed on 
])ieces of seed potatoes left on 
the surface and will some- 
times dig into the soil in 

search of the tender sprouts. Fig. 82. — The Colorado potato beetle, 
r,^, PIP , • 1 Pfigs and newly hatched larvae 

iney teed tor a tune on the (enlarged). 

tender foliage and then, after 

pairing, deposit their eggs on end in masses on the under- 
side of the leaves (Fig. 82). Each mass contains from four 
or five to nearly seventy eggs with an average of about twenty- 
five. The egg is about ^ inch in length, elongate oval and 
orange in color, with the surface smooth and shining. The 
egg is glued to the leaf with a small mass of orange-colored 
material. The female is capable of laying from 200 to over 
1800 eggs with a probable average of 400 or 500. The eggs 
do not ripen continuously but in successive batches; all the 
eggs which ripen at a given time may be deposited in one or 

L 



146 MANUAL OF VEGETABLE-GARDEN INSECTS 




iiKire clusters. The average length of the egg-laying period 
in the field is probably between four and six weeks, but under 

cage conditions 
the beetles have 
continued to lay 
eggs for ten weeks 
or more. The 
eggs hatch in four 
to nine days. On 
h a t c h i n g, the 
young larva be- 
gins at once to 
feed on the leaves. 
In the first stage 
it is about yo i'lch 
in length, dark 
red in color with 
the head, thoracic 
shield and legs black and with a double row of black spots 
along each side of the body. In the course of its development 
the larva passes through three or 
four stages according to different 
observers. In the last stage it is 
about f inch in length ; the head, 
legs and posterior part of the cervi- 
cal shield are black; the body is 
red, lighter than in the first stage 
and there are two rows of distinct 
black spots on each side ; the ab- 
domen is strongly convex and is 
much larger than the head and 
thorax (Fig. 83). The larvse be- 
come full-grown in ten days to three weeks and then enter 
the ground to a depth of several inches where they transform 



Fig. 83. — Larvs of the Colorado potato beetle ( X f). 




Fig. !S4. — Pupa ot the C'olo- 
rado potato beetle ( X 4). 



POTATO INSECTS 



147 



in earthen cells to pupje. The pupa is a little over ^ inch in 
length and orange-yellow in color (Fig. 84). After a pupal 
period of five to ten days the adults emerge. The beetle is 
about f inch in length, strongly convex above and yellow in 
color. The head has a triangular black spot between the 
eyes ; the prothorax is marked with two divergent elongate 
black spots near the middle and four to six smaller spots on 
each side. Each wing-cover has the sutural margin and five 
narrow stripes black, the second and third united at the tip ; 
the knees and tarsi are blackish (Fig. 85). The beetles are 
often called hard-shells to distinguish them from the larvae, 
which are known as slugs or soft-shells. 
After feeding a few days, the beetles may 
either go into the ground for a more or 
less extended period of aestivation or they 
may immediately lay eggs for a second 
generation. Owing to the long period 
over which egg-laying takes place, all 
stages of the insect may be found at any 
time during the latter part of the summer. 
There are normally two generations pro- 
duced annually but in some cases a small 

third brood of larvae may develop and in JNIontana it is 
claimed that there is only one generation. 




Fig. 85. — The Colorado 
potato beetle (X 25). 



Control. 

For many years paris green has been the standard insecti- 
cide for the control of the Colorado potato beetle. It is some- 
times applied in the form of a dust, 1 pound in 50 pounds of 
land plaster or hydrated lime. It is more effective, however, 
when applied in water, 1 pound in 50 gallons. To avoid burn- 
ing the foliage, 2 pounds of lime should be added. Paris green 
is most effective and least liable to injure the vines when ap- 
plied with bordeaux mixture as used for the control of fungous 



148 MANUAL OF VEGETABLE-GARDEN INSECTS 

diseases. From 8 ounces to 1 pound should be added to each 
50 gallons, depending on the thoroughness of the application. 
Arsenate of lead, 3 or 4 pounds of the paste to 50 gallons, has 
also been found satisfactory. It adheres to the foliage better 
than paris green but does not kill the insects so quickly. It 
may be used either in water or in bordeaux mixture. Arsenate 
of lead may also be applied in the dry or powdered form diluted 
with sulfur, gypsum or hydrated lime. Experiments in New 
Jersey, however, have shown that, on the whole, this treatment 
does not give as good results in yield as are obtained by spray- 
ing with bordeaux and arsenate of lead. When expense is an 
important item, sodium arsenite may be used instead of paris 
green or arsenate of lead with satisfactory results, at the rate 
of 1 quart of the stock solution to 50 gallons of bordeaux mix- 
ture. For the preparation of sodium arsenite see page 369. 

The first application for the potato beetle should be made 
about the time the eggs are hatching. The larvse are much 
harder to kill when nearly full-grown and they have then 
caused the greater part of the damage. It sometimes happens 
that the eggs are deposited in patches in the field so that the 
infestation is not general. In such cases it is a good plan to 
treat these areas early and not wait till the whole field can be 
sprayed. In Virginia, where potatoes are seriously injured 
by the over-wintered beetles, just as the plants are peeping 
through the ground, it is recommended that they be dusted 
with a mixture consisting of 1 pound of paris green and 20 to 
30 pounds of hydrated lime. This application is intended to 
protect the plants until they are large enough to be sprayed. 

In the home garden where only a few potatoes are grown, 
it is practicable to hand-pick the beetles into pans containing 
a little kerosene oil or the plants may be dusted with paris 
green or powdered arsenate of lead diluted with land plaster, 
hydrated lime or some similar substance. 

For the protection of tomato plants, arsenate of lead should 



POTATO INSECTS 



149 



be used instead of paris green because of the danger of foliage 
injury by the hitter. 

References 

Riley, Potato pests, N. Y. 1876. 

Tower, An investigation of evolution in Chrysomelid beetles of the 

genus Leptinotarsa. Washington. 190(5. 
U. S. Bur. Ent. Cire. 87. 1907. 

Girault and Rosenfeld, Psyche, 14, pp. 4'>-~u. 1907. 
Girault, Ann. Ent. 8oe. Am., 1, pp. 155-178. 1908. 
U. S. Bur. Ent. Bull. 82, pp. 1-8. 1909. 
Girault and Zetek, Ann. Ent. Soc. Am., 4, pp. 71-83. 1911. 
Va. Truck Exp. Sta. Bull. 14. 1915. 
Johnson and Ballinger, Jour. Agr. Research, 5, pp. 917-925. 1916. 



The Three-Lined Potato Beetle 

Lema trilineata 01i\'ier 

Throughout the United States and Canada east of the Rocky 
IMountains, potatoes and tomatoes are sometimes attacked 
by the larvie of a ycHowish leaf- 
beetle (Fig. 86) about \ inch in 
length. The head and thorax are 
reddish yellow, the latter constricted 
at the middle and usually marketl 
with two black spots. The wing- 
covers are reddish yellow and marked 
with three black stripes. The an- 
tennae are black, except the base, 
and the legs are reddish yellow 
with the outer half of the tibia? 
and tarsi black. A closely related 
species, Lema nigrocittata Guerin- 
Meneville, occurs in California ; by 
some it is considered identical with the eastern species. 

The three-lined potato beetle probably hibernates in the 
adult condition, the beetles appearing in early spring. They 




Fig. SG. — The three-lined 
potato beetle (X 3^). 



150 MANUAL OF VEGETABLE-GARDEN INSECTS 

feed at first on various wild plants, preferring solanaceous 
weeds. As soon as potato and tomato plants are available, 
the beetles migrate to them and deposit their eggs usually on 
the underside of the leaves in clusters of six to ten. Each 
egg is about -j^ inch in length, smooth, oval and yellowish 
in color. The eggs hatch in about two weeks and the young 
larvae at first feed in a row side by side, beginning at the edge 
of the leaf and moving backward as they devour the tissue. 
When mature the larva is about ^ inch in length with the head, 
thoracic shield and legs black and the body yellowish. The 
body of the larva is kept moist and sticky by a secretion and 
is usually covered with a coating of excrement. The grubs 
become full-grown in about two weeks and then enter the ground 
where they construct earthen cells lined with a gelatinous 
secretion from the mouth. The pupal period occupies about 
two weeks. There are said to be two generations annually. 
The three-lined potato beetle has never been reported as 
a very important pest but it may occasionally become trouble- 
some when conditions are favorable for its development. It 
may be controlled by spraying m- ith arsenical poisons as recom- 
mended for the Colorado potato beetle. 

References 

Harris, Insects injuriotis to vegetation, pp. 9.5-9G. 1841. 
Fitch, 10th Rept. N. Y. State Ent., N. Y. State Agr. Soc, 24, pp. 441- 
447. 1864. 

The Potato Aphis 

Macrosiphum solanifolii Ashmead 

Although the potato aphis is generally distributed through- 
out the United States and southern Canada, injurious out- 
breaks have been reported only from ]\Iaine, Connecticut, 
New York, New Jersey, Pennsylvania, Ohio, Illinois, Iowa, 
Kentucky, Maryland and Virginia and the provinces of Ontario, 



POTATO INSECTS 151 

Quebec and Prince Edward Island. \Yhile the insect is doubt- 
less present in small numbers each year in these states, it has 
appeared in destructive abundance only at intervals of several 
years. This plant-louse is not confined to potatoes but also 
injures tomato, eggplant, pea, turnip, beet, spinach, pepper, 
asparagus, sunflower and sweet potato and has been found 
infesting various weeds such as ground cherry, Jamestown 
weed, ragweed, lamb's quarters and wild lettuce. It is also 
found on canna, hollyhock, gladiolus, iris and matrimony vine. 
It was originally described from specimens collected on the 
pepper-vine, Solanum jasminoides, in Florida. 

The potato aphis passes the winter in the form of shining 
brownish black eggs on the rose and possibly on other peren- 
nials. The eggs hatch about the time the leaf-buds are opening 
and the young aphids reach maturity on this plant. Probably 
in the second or third generation, most of the aphids migrate 
to the potato and other herbaceous food plants. Throughout 
the entire growing season, only female aphids are produced 
and these give birth to living young. Both winged and wing- 
less females occur through- 
out the season. In warm 
weather a female reaches 
maturity in ten days to 
two weeks and may gi\e 
birth to more than fifty 
young over a period of 
about fourteen days. The 
adult winged viviparous 

„ , . 1 i 1 • 1 Fig. 87. — The winged viviparous female 

female is about i mch, potato aphis (x 5). 

and the wingless form 

about ^ inch in length (Figs. 87 and 88). Both forms are 
usually green but pink individuals are common. The potato 
aphis closely resemliles the pea aphis but may be dis- 
tinguished under the microscope by having the tip of the 




152 MANUAL OF VEGETABLE-GARDEN INSECTS 

cornicles reticulate for a short distance instead of being im- 
bricated throughout. At the approach of cold weather, 
the winged forms migrate to the rose and there produce a 
generation of winged males and wingless egg-laying females. 
In Maine the winter eggs are laid in late September. 




Fig. 88. — The wingless viviparous female potato aphis ( X 7i) 



The time at which the pest becomes destructive to potatoes 
varies from year to year. In Maine it has been found most 
abundant in August, but in 1917, when the outbreak was the 
most extensive and destructive so far recorded, the attack be- 
came serious in New York in early July and in Ohio in late 
June. On potatoes the aphids cluster on the underside of the 
leaves, causing them to curl downward. They also infest 
the tender tips and the blossom stems. When badly infested, 
the vines soon become covered with the sticky honey dew 
secreted by the aphids. The tips are first killed, and in 1917 
many large fields were observed in which all the plants were 
killed to the ground. Even when the vines are only partly 
killed, the size and qualit}^ of the crop is seriously affected. 
On tomatoes the lice also infest the leaves but cause their 
greatest injury by attacking the blossom stems and young 



POTATO INSECTS 153 

fruits. The blossoms arc killed, the fruit is dwarfed and the 
ripening period is delayed so that in many eases the crop is a 
total loss. 

Control. 

The potato aphis can be killed by spraying with "Black 
Leaf 40" tobacco extract, ^ pint in 50 gallons of bordeaux 
mixture. If for any reason bordeaux mixture is not used, the 
"Black Leaf 40" may be diluted with water at the same rate 
but in this case 3 or 4 pounds of soap should be added to each 
50 gallons. Since many of the aphids are on the underside 
of the leaves, it is necessary to have the spray directed upward. 
Some potato-sprayers have the nozzles arranged to do this. 
Other potato-sprayers may be adapted for this work by remov- 
ing the nozzles and inserting a l-foot extension directed down- 
ward. On the end of this extension a T-coupling is attached. 
To each side of the T-coupling is joined a piece of pipe 6 inches 
in length directed at right angles to the rows and equipped 
with a 45° angle nozzle, so attached as to throw the spray 
obliquely upward and backward. This outfit can be used to 
advantage as long as the plants are upright. After the vines 
are down, effecti\e work can be done by using two leads of hose 
10 or 12 feet in length equipped with 4-foot extension rods 
and angle nozzles. With this outfit a traction pump will not 
deliver the liquid in sufficient quantity and it is, therefore, 
necessary either to operate the pump by hand or with a gaso- 
line engine. It requires at least 100 gallons of the spray mate- 
rial to the acre to be effective. It is usually better to use the 
tobacco extract in combination with the bordeaux mixture 
than with water and soap because of the value of the bordeaux 
in pre\enting potato blight. Furthermore, it has been ob- 
served that potatoes regularly sprayed with ])()rdeaux mixture 
are less likely to be seriously infested with the a})hid than un- 
treated vines. Where there is any reason to fear an outbreak 



154 MANUAL OF VEGETABLE-GARDEN INSECTS 

of the potato aphis, careful watch should be kept of the plants 
and when the lice begin to appear in any abundance, steps should 
be taken to destroy them before the vines become stunted. 

The potato aphis is often aided in its destructive work on 
potato and other garden plants by the spinach aphis, for a 
discussion of which see page 105. 

References 

Maine Agr. Exp. Sta. Biill. 147. 1907. 
Maine Agr. Exp. Sta. Bull. 190. 1911. 
Maine Agr. Exp. Sta. Bull. 242. 1915. 
Ohio Agr. Exp. Sta. Bull. 317. 1917. 

The Apple Leafiioppek 

Empoasca viali Le Baron 

The well-known apple leafhopper, a troublesome pest on 
apple nursery stock, often breeds during the summer on potato 
vines. The insect passes the winter in the egg stage on the 
apple and the first brood of nymphs develops on this plant, 
reaching maturity about a month after hatching. Some of 
the adults of the second and later broods migrate to potato 
and there insert their small, whitish, elongate, slightly curved 
eggs about ^o i'lch in length, in the tender parts of the potato 
vines. The eggs hatch in a few days and the young nv'mphs, 
in company with the adults already present on the vines, feed 
on the underside of the leaves, causing them to curl and stunt- 
ing the tender growing tips. The injury is most noticeable 
in periods of drought. The young hoppers pass through five 
nymphal stages, acquiring wings at the fifth molt. The 
nymphs are pale greenish and in the last stage are about yV 
inch in length. The adult leafhoppers are about ^ incli long and 
of a pale yellowish green color, with six or eight distinguishing 
white spots on the front margin of the pronotum (Fig. 89). 



POTATO INSECTS 



155 



When disturbed the nymphs run in all directions but the adults 

can jump quickly and fly away, often rising in swarms as one 

walks through an infested field. About a month is required 

for the completion of the life cycle. There 

are three generations of the insect a season 

on the potato. In the fall the adults find 

their way back to the apple and there 

deposit the winter eggs in the bark of the 

smaller branches, just below the epidermis, 

two-year-old wood being most often selected. 

The position of the egg is indicated by a 

low blister-like ele^'ation of the bark about 

3^ inch in length and about half as wide. 

The apple leafhopper has also been 
reported as causing spots on the white 
stalks of celery and as feeding on sugar- 
beets and beans. It is rarely of sufficient importance on potato 
to warrant special applications of insecticides. The nymphs 
may be killed by spraying with "Black Leaf 40" tobacco 
extract as recommended for the control of the potato aphis. 




Fig. 89. — The i.pple 
leafhopper, adult 

(X 11;. 



References 

Minn. Agr. Exp. Sta. Bull. 112, pp. 145-164. 1908. 

Iowa Agr. E.xp. Sta. Bull. 111. 1910. 

Iowa Agr. Exp. Sta. Bull. 1.5.^), pp. 394-400. 1915. 



The Potato Stalk-Weevil 

Trichohnris trinotala Say 

Throughout the northern states from New York to North 
Carolina westward to Kansas, Nebraska, Texas and southern 
California, potatoes are subject to the attacks of a small weevil, 
the larva of which bores in the stalk. This insect has been 
found most injurious in Kansas, Nebraska and Iowa, but more 



156 MANUAL OF VEGETABLE-GARDEN INSECTS 



or less serious outbreaks haAe occurred in southeastern Penn- 
sylvania and in New Jersey. In New York the insect has been 
troublesome in the upper Hudson River Valley and in Ontario 
on Pelee Island in Lake Erie. Its wild food plants include a 
number of solanaceous weeds, such as ground cherry, James- 
town weed, buffalo bur and horse nettle and it has also been 
recorded as infesting cocklebur. p]ggplant is sometimes at- 
tacked and there is at least one record of injury to tomato. 
Early potatoes are more subject to injury than late varieties. 
The adult (Fig. 90) is a snout-beetle, about ^ inch in length, 
bluish gray in color with the head and scutellum black and 
with a black spot on each side near the 
margin at the junction of the prothorax 
and the base of the wing-covers. The 
ground color of the beetle is black, its 
blue-gray color being derived from a 
thick covering of narrow scales. The 
beetles appear in the field in spring 
and feed for a time on the stems of 
the potato which they puncture with 
their beaks. The female inserts her 
eggs singly in the stalk or branches 
and sometimes even in the leaf petioles. 
In ovipositing, she first hollows out a cavity with her beak 
and then turning around places the egg in the puncture. 
The egg is oval, yellowish white and about ^V inch in length. 
The eggs hatch in a week to eleven days and the young 
grub burrows down through the pith several inches and then 
turning about retraces its course. When nearly full-grown, 
it eats out the entire pith for some distance. When mature 
the larva is | to :^ inch in length, yellowish white, with the 
head brownish. Legs are lacking. The presence of the 
grubs is indicated by a wilting and dying of the leaves, 
while the stem may remain green for some time. Several 




Fig. 90. ~ The potato 
.stalk-wccvil ( X 6|). 



i 



POTATO INSECTS 157 

larvse may infest the same stalk and often kill the entire plant. 
When full-grown, the grub eats out an exit hole for the future 
beetle nearly to the surface but does not penetrate the outer 
bark. It then constructs a cell or cocoon of fibers stripped 
from the wall of the burrow and then transforms into a creamy 
white pupa about ^ inch in length. In Kansas the larvae 
begin to pupate about the middle of July and in New Jersey 
the last of the month but some do not reach maturity till early 
fall and in a few cases have been known to enter the winter 
in this stage. The insect spends from eight to fifteen days or 
longer in the pupal stage. Although some of the beetles are 
to be found in the stalks in early August, they do not usually 
emerge until the following spring, but when the stalks are broken 
open they may be forced to seek winter quarters elsewhere. 
There is only one generation annually. 

Control. 

The potato stalk-weevil is best held in check by collecting 
and burning the vines soon after the crop is dug. If this is 
practiced regularly and if all solanaceous weeds in which the 
weevils breed are reduced to a minimum by clean farming, 
the pest can be prevented from doing any serious damage. 

References 

N. J. Agr. Exp. Sta. Bull. 109, pp. 25-32. 1895. 
Kans. Agr. Exp. Sta. Bull. 82. 1899. 
U. S. Div. Ent. Bull. 33, pp. 9-18. 1902. 

The Com.mon Stalk-Borer 

Pnpnipemn nitela Guenee 

The common stalk-borer is generally distributed throughout 
the United States, and Canada east of the Rocky Mountains. 
Although the insect is usually present in small numbers, oc- 
casionally serious outbreaks occur locally. The borers attack 



158 MANUAL OF VEGETABLE-GARDEN INSECTS 

potato, tomato, eggplant, pepper, corn, bean, rhubarb, spinach, 
cauhflower, dahlia, aster, chrysanthemum, lily, hollyhock, 
golden glow, peony, sunflower, castor bean and several other 
ornamental plants. Their wild food plants include ragweed, 
great ragweed, cocklebur, burdock and pigweed. Wheat, 
rye, barley, blue-grass and timothy are sometimes attacked 
as well as the tender shoots of raspberry, blackberry, currant 
and gooseberry. 

The insect passes the winter in the egg stage on the stalks 
of such plants as ragweed, dock, pigweed and burdock. The 
egg is -^ inch in diameter, brownish gray, globular, slightly 
flattened and with numerous ridges radiating from the tip. 
The eggs hatch in late May or early June and the young cater- 
pillar begins feeding on the first suitable plant that it finds. 
It may first feed as a miner in the leaves for a few days and then 
burrow into the stem. Ragweed, pigweed, blue-grass and 
timothy, as well as wheat and other grains, are often attacked 
by the young larvje. Many of these plants are soon killed and 
the caterpillars then migrate to other plants. It usually hap- 
pens that the young larvae get their start in the rank weeds 
surrounding the field or garden and when forced to migrate 
in search of fresh food attack the cultivated crops. It has 
often been noticed that corn is most subject to infestation along 
the edge of the field and that other crops, such as potatoes and 
tomatoes, are more liable to injury when grown in small gardens 
than when planted in large open fields. In New York the cat- 
erpillars usually attract most attention by their injuries to 
garden plants from the middle of June to the last of July. The 
caterpillar until the next to the last molt is dull brown, the head, 
cervical and anal shields honey-yellow% smooth and shining, 
with a black stripe on each side of the head and on each side 
of the cervical and anal shields. Each end of the body is 
grayish brown with a white dorsal stripe and two white stripes 
on each side. The integument is apparently thinner from the 



POTATO INSECTS 



159 




Fig. 91. — The common stalk-boFvT, 
larva (X U). 



middle of tlie tliird thoracic segment to tlie middle of the 
fourth abdominal segment, dirty greenish gray with the white 
dorsal stripe only present, the lateral stripes being broadly 
interrupted. This caterpillar is distinguished from its near 
relatives by having but one tubercle behind the spiracle on 
the eighth abdominal segment ; 
by lacking the large plates on 
the second and third thoracic 
segments and by the presence 
of a pair of small plates on 
the next to the last abdominal 
segment. The full-grown caterpillar is slightly less than 1^ 
inches in length and similar to the preceding stages except 
that the stripes on the body gradually fade out into a dirty 
greenish gray and finally disappear shortly before pupation 
occurs (Fig. 91). The caterpillars reach maturity in August 
and transform, usually in the burrow, into a brownish pupa f 

inch in length. The moths 
emerge in September and 
October and deposit their 
eggs on the stalks of their 
food plants. The pupal 
period lasts about three 
weeks. 

There are two varieties 
of the moth. In the 
typical form (P. nifrlo), 
the front wings are grayish 
brown with a slight olive 
tinge, lightly dusted with white. The usual outer line is 
pale and bent inw^ard about one fourth of the distance from 
the front margin of the wing and then runs nearly straight 
across the inner margin. The hind wings are slightly paler 
in color except towards the margin and on the veins. In the 



ft^ 


1^ ~"\ 


/^^|tf| 


■||M 


1^ 




^* 


PI 


w^K^^ 


\ 


■ m 


' ^ ^^s^s^ 



Fig. 92. — Moth of the common stalk- 
borer, variety P. ntbris (X l\). 



160 MANUAL OF VEGETABLE-GARDEN INSECTS 

other variety (P. nchris), there are three disthict white spots 
nearly one third the distance from the base of the wing, the 
middle one being the smallest (Fig. 92). Just inside the outer 
line near the front margin of the wing is a fine yellow crescent 
with a yellow spot lying within its concavity and with three 
to five white dots on its low^er and inner side. There is only 
one generation annually. 

Control. 

No satisfactory method of reaching the borers in their bur- 
rows is known. Much loss may be avoided, however, by de- 
stroying all rank weeds in which the caterpillars live growling 
in the vicinity of the garden and along the edges of fields planted 
to tomatoes, potatoes, corn and other plants especially subject 
to injury. 

References 

N. J. Agr. Exp. Sta. Rept. for 1905, pp. 584-587. 

111. Agr. Exp. Sta. Bull. 95, pp. 374-377. 1904. 

Franklin, r2th Rept. State Ent. Minn., pp. 197-198. 1908. 

And in other papers published by Washburn. 

The Burdock Borer 

Papaipema cataphracta Grote 

Potato, tomato, rhubarb and corn have been reported in 
Canada as injured by a stalk-borer closely related to the species 
last treated. The insect ranges throughout the northern states 
and Canada westward to Minnesota. The favorite food 
plants of this caterpillar are burdock and thistle, but sunflower, 
ragweed, golden glow, hollyhock and many other ornamental 
plants are also subject to attack. The work of the borers 
becomes noticeable in July, specimens one third to full-grown 
being found till the first of August. The caterpillar is very 
similar to the common stalk-borer but the stripes run from end 



POTATO INSECTS 161 

to end with no interruption in the middle. The caterpillars 
reach maturity in August and transform to brownish pup;e 
within the burrows. The moths are on the wing in September 
and October. They have an expanse of about 1-^ inches. The 
ground color of the front wings is light yellow, dusted with 
brown, the outer margin grayish, leaving a yellow^ spot at the 
apex. The outer line runs as in P. nifcia and is double and 
the wing is spotted in much the same way as in the variety 
nebris of that species. The hind wings are light brown. The 
eggs are deposited singly in cracks and crevices on the stems 
of the food plants in the fall but do not hatch until the follow- 
ing spring. There is only one generation annually. 

The injury inflicted by the burdock borer may be avoided 
by adopting the measures recommended for the common 
stalk-borer. 

The Potato Scab Gnat 

Pnyxia scabiei Hopkins 

Potatoes are sometimes injured by a small, white, black- 
headed maggot, about ^ inch in length, that causes an injury 
similar to that produced by the scab fungus. Outbreaks of 
this insect have been recorded in West Virginia and in Ohio 
and infested potatoes have been shipped from Philadelphia. 
The adult insects have been found in New York and have been 
collected under dead leaves in the woods in Missouri. It is 
probable that the normal food of the scab gnat maggot is de- 
caying vegetable matter. Under certain conditions, however, 
it will attack potatoes in the field and in storage. The 
maggots have also been found injuring peony bulbs in Pennsyl- 
vania. Potatoes are more subject to injury when grown in 
low ground where there is an abundance of humus or when 
stored in warm, damp cellars. 

The female fly is -^ to ^^ inch in length, pale in color and 
without wings. The male is somewhat dusky, smaller than 

M 



162 MANUAL OF VEGETABLE-GARDEN INSECTS 

the female and occurs in two forms, one with normal functional 
wings and the other with abbreviated wings. The fly deposits 
her small, white, oblong eggs, about y^s "^ch in length, on the 
surface of the potato. The eggs hatch in five or six days and 
the young maggot works its way into the tuber, usually taking 
advantage of a scab spot or other injury. The maggots attack 
the healthy tissue and under favorable conditions of tempera- 
ture and moisture will continue their work generation after 
generation until the tuber is completely destroyed. The mag- 
gots become mature in about a week and then transform to 
delicate white pupte in flimsy silken cocoons either in the soil 
or on the surface of the tuber. The adults emerge in three or 
four days. From twenty to twenty-five days are required for 
the insect to complete its life cycle. 

Control. 

Serious injury by the potato scab gnat is of rare occurrence. 
Only uninfested seed potatoes should be planted and land on 
which the crop has been infected should not be used for potatoes 
the following year. Potatoes grown in dry, light soil are not 
likely to be attacked. 

References 

W. Va. Agr. Exp. Sta. Sp. Bull. 2, pp. 97-111. 1895. 
Hopkins, Proc. Ent. Soc. Wash., 3, pp. 149-159. 1895. 

The Potato Tuber Moth 

Phthorimcea operculella Zeller 

Potatoes in California and Texas are subject to attack by 
a small whitish caterpillar about ^ inch in length that riddles 
the tubers with burrows, causing them to decay. The potato 
tuber moth is also a troublesome tobacco pest and when feeding 
on this plant is known as the split-worm or tobacco leaf-miner. 



i 



POTATO INSECTS 163 

The insect ranges from Virginia to Colorado and southward 
and on the Pacific Coast is present in CaHfornia and Washing- 
ton. It is also known as a serious enemy of the potato in 
Australia, New Zealand, the Mediterranean region and South 
Africa. Besides potato and tobacco, the insect sometimes 
attacks eggplant and tomato, mining the leaves and stalks 
and biuTowing in the fruit. Its wild food plants include com- 
mon nightshade, horse-nettle, Jamestown weed and several 
other solanaceous plants. 

The potato tuber moth has been studied most carefully in 
California and in France. The caterpillars not only infest 
the tubers both in the field and in storage but also mine the 
leaves and petioles and bore into the stalks. The parent moth 
has an expanse of a little more than ^ inch. The front wings 
are yellowish brown, more or less spotted and mottled with 
dark brown. The hind wings are light yellowish brown and 
provided with a long fringe. The moths appear in the field 
early in the spring and deposit their eggs singly, usually on the 
underside of the potato leaves. The egg is oval, about -^V inch 
in length, pearly white with a faint iridescence, becoming 
leaden gray just before hatching. The eggs hatch in three to 
five days. On hatching, the young larva bores into the leaf 
where it produces a blotch mine. As it increases in size, it 
may migrate to another leaf or bore down through the petiole 
and into the stalk, causing the branch to wilt and die. When 
full-grown the caterpillar is about ^ inch in length, white, 
tinged with pink or greenish above, with the head and cervical 
shield dark brown and with the small anal plate light brown. 
It reaches maturity in two weeks to seventeen days in warm 
weather. When ready to pupate, the larva constructs a small 
grayish silken cocoon about ^ inch in length, which is covered 
with dirt and pieces of excrement. The cocoons are sometimes 
found in the opening of the burrow, in trash at the base of the 
plant or more commonly in the dried leaves still clinging to the 



164 MANUAL OF VEGETABLE-GARDEN INSECTS 

vine. The pupa is brown, becoming darker with age and is 
about f inch in length. The insect remains in the pupal stage 
from a week to ten days in warm weather. In two or three 
days after emergence, the moths lay eggs for another brood. 
Reproduction is continuous throughout the season. 

After the tubers have formed, they may become infested 
in several ways. Some of the caterpillars may leave the stalks 
and migrate to the potatoes. When the soil is loose and the 
potatoes are near the surface, the moths may work their way 
down through the cracks and lay their eggs on the tubers. 
When the potatoes are planted shallow some of the tubers 
may become exposed and the moths will lay their eggs on them. 
Potatoes are most likely to become infested at digging time. 
If left exposed in the field during late afternoon or overnight, 
eggs are laid on them in abundance. When the piles of pota- 
toes are covered with infested vines, the caterpillars may leave 
the stalks and enter the tubers. When infested tubers are 
placed in storage, the insect will continue breeding throughout 
the winter provided the temperature does not fall below 40° 
or 50° F. When deposited on the tubers, the eggs are usually 
placed around the eyes or on the edge of holes made by the 
larvse. On hatching the young caterpillar soon works its way 
into the potato, throwing out a small mass of frass through 
the opening. The young caterpillars at first burrow just 
underneath the skin but when half grown or more work their 
way into the flesh, sometimes quite to the center of the tuber. 
The burrow is lined with a silken tube through which the larva 
can move back and forth readily. When about to pupate, 
the larva leaves the tuber and in some crack or corner or be- 
tween two potatoes spins its cocoon. In storage the insect 
will continue to breed as long as any potatoes remain in con- 
dition to serve as food for the larvae. Five or six generations 
may develop in the course of a year. 

Under storage conditions, a longer period is required for the 



POTATO INSECTS 1G5 

completion of the life cycle because of the lower temperature. 
Under such conditions the egg stage requires a week or ten 
days, the larva about six weeks and the pupa two weeks or over. 

Control. 

The injuries caused to the vines by the potato tuber moth 
are not in themselves serious. The great loss comes from the 
infested tubers. This may be prevented in large measure by 
planting the potatoes rather deep and by keeping them care- 
fully hilled so as not to allow any of the tubers to be exposed 
on which the moths can deposit their eggs. Care should be 
taken at digging time not to leave potatoes exposed overnight 
while the moths are laying. Piles of potatoes should not be 
covered with infested vines since the larvae will leave the stalks 
when they begin to wilt and enter the tubers. After the pota- 
toes have been placed in storage, they should be examined at 
frequent intervals and if any are found to be infested, they 
should be fumigated with carbon bisulfid at the rate of 2 
pounds to 1000 cubic feet of space, allowing the fumigation 
to continue for about forty-eight hours. This should be re- 
peated at intervals of about a week in summer or two weeks 
in winter. Directions for fumigation will be found on page 380. 

Where the potato tuber moth is abundant, it is not advisable 
to plant potatoes on the same land for two years in succession. 
By practicing rotation of crops and by destroying all solaiia- 
ceous weeds on which the insect may breed, much loss may be 
avoided. 

References 

Cal. Agr. Exp. Sta. Bull. 135. 1901. 

Picard, Ann. Service Epiphyties, 1, pp. 106-176. 1913. 

U. S. Farm. Bull. 5.57. 1913. 

U. S. Dept. Agr. Bull. 59. 1914. 

U. S. Dcpt. Agr. Bull. 427. 1917. 



166 MANUAL OF VEGETABLE-GARDEN INSECTS 



Other Potato Insects 

Corn ear-worm : 211 

Southern corn root-worm : 222 

Cabbage looper : 8 

Garden webworm : 18 

Seed-corn maggot : 36 

Harlequin cabbage bug : 38 

Serpentine leaf-miner : 4G 

False chinch-bug : 47 

Yellow bear caterpillar : 357 

Carrot beetle : 185 

Adelphocoris rapidus : 195 

Sugar-beet webworm : 97 

Spinach apliis : 105 

Tomato worms : 168 

Western twelve-spotted cucumber beetle : 114 

Belted cucumber beetle : 115 

Southern leaf -footed plant-bug: 121 

Garden springtail : 139 

Grape colaspis : 67 

Bean thrips : 69 

Garden flea-hopper : 77 

Eggplant tortoise beetle : 177 

Eggplant lace-bug : 178 

Spotted cutworm : 262 

Greasy cutworm : 265 

Dark-sided cutworm : 268 

Striped cutworm : 270 

Shagreened cutworm : 272 

Clay-backed cutworm : 274 

Variegated cutworm : 276 

Army cutworm : 287 

Fall army-worm : 292 

Beet army-worm : 294 

Yellow-striped army-worm : 295 

Semi-tropical army-worm : 297 

Striped blister-beetle : 302 

Margined blister-beetle : 305 

Gray blister-beetle : 306 

Ash-gray blister-beetle : 306 

Black blister-beetle : 307 

Spotted blister-beetle : 309 

Two-spotted blister-beetle : 309 J 

Macrobasis longicollis: 310 1 

i 



POTATO INSECTS 167 



Immaculate blister-beetle : 310 
Segmented black blister-beetle : 310 
Panther blister-beetle : 311 
Crow blister-beetle : 311 
Potato flea-beetle : 314 
Western potato flea-beetle : 318 
Tobacco flea-beetle : 319 
Eggplant flea-beetle : 320 
Pale-striped flea-beetle : 321 
Red-headed flea-beetle : 323 
Smartweed flea-beetle : 323 
Hop flea-beetle : 335 
Root-knot nematode : 338 
MilUpedes: 342 
Wheat wireworm : 348 
Sugar-beet wireworm : 349 
Slugs : 354 



CHAPTER VII 

TOMATO INSECTS 

Many potato insects also attack the tomato. The most 
important of these are the potato flea-beetle and the Colorado 
potato beetle. In the South, the corn ear-worm is usually 
the most destructive pest to be contended with and the tomato 
worms often cause serious loss. 

The Tomato Worms 

Throughout the United States and southern Canada, tomatoes 
are subject to attack by large greenish or brownish caterpillars 
3 or 4 inches in length which are provided with a sharp horn 
on the back near the hind end of the body. They are also 
known as horn-worms and tobacco worms. These tomato 
worms belong to two distinct species. The areas occupied by 
the two forms overlap to a considerable extent. Throughout 
the greater part of the United States, caterpillars of both species 
are found feeding together, the relative abundance varying 
from place to place and from year to year. The northern form 
ranges from Canada to Florida westward to the Pacific. The 
southern species breeds from Massachusetts, New Jersey, 
Ohio and Illinois southward through the West Indies to 
Patagonia. Both species occur in California. In addition 
to tomato, eggplant, potato and pepper are sometimes 
attacked. 

168 



TOMATO INSECTS 



169 



The northern tomato worm, PUegethontius quinquemaculata 
Haworth 

The adult of the northern tomato worm is a moth having an 
expanse of 4 to 5 inches (Fig. 93). The front wings are ashy 




^*^^^:rfiS£W^ ^ y 




Fig. 93. — The northern tomato worm moth ( X J). 

gray marked with irregular brown and black lines. The hind 

wings are whitish with a broad gray band on the outer margin 

and crossed with four black bands, the middle pair being 

sharply zigzag. The abdomen is 

gray marked with a narrow 

median black line and with a row 

of large yellow spots on each 

side which are surrounded with 

black. On the posterior margin 

of each segment are two white 

spots on each side, one above 

and one below the yellow spot 

of the succeeding segment. The 

moths appear on the wing in May or June. They fly in the 

evening or on dark days and may be seen hovering over flowers 




Fig. 94. — Egg of the northern 
tomato worm (X 7). 



170 MANUAL OF VEGETABLE-GARDEN INSECTS 

from which they suck the nectar. The mouth is provided with 
a long sucking tube from 2^ to 5 inches in length which when 
not in use is coiled under the head. The eggs are deposited 
singly, usually on the underside of the leaves. The. egg (Fig. 
94) is globular, nearly ys inch in diameter and greenish yellow 




Fig. 95. — Full-grown northern tomato worm (X I). 



in color. The eggs hatch in three to eight days and the young 
caterpillars begin feeding on the leaves. They grow rapidly, 
reaching maturity in three weeks to a month. The larger 
caterpillars feed ravenously and will strip a tomato vine in a 
few days. The full-grown caterpillar (Fig. 95) is 3 or 4 inches 

in length and varies 
in color from green 
to dark brown. Each 
segment of the abdo- 
men is marked on the 
side just above the 
spiracle with a greenish white oblique stripe which, with a 
similar horizontal stripe below the spiracle, forms a V with 
the apex pointed forward. The horn at the posterior end of 
the body is green with the sides black. When disturbed the 
caterpillar has the curious habit of elevating the front part 




Fig. <J6. 



Pupa of northern tomato worm in 
its cell (X i). 




TOMATO INSECTS 171 

of the body and drawing in the head, in which position it will 
remain motionless for a long time. When mature the cater- 
pillar goes into the ground a few inches and there in an earthen 
cell transforms to a 
dark brown pupa (Figs. 
96 and 97) about 2 
inches in length. The 
sucking tube of the 

future moth is inclosed F^^- ^7. — Pupa of the northern tomato worm 
, (Xl|). 

m a separate case irom 

one third to nearly half as long as the pupa, resembling the 
handle of a pitcher. The number of generations varies with 
the length of the season; in the North there is apparently 
only one, in INIaryland and Kentucky there are two and in 
Florida there are said to be three or four. 

The southern tomato ivorm, Phlegethontius sexta Johannsen 

The moth of the southern tomato worm is similar to that of 
the northern species but the ground color of the wings is 
brownish gray instead of ash-gray. There is usually a small 
white spot near the middle of the front wing and the interme- 
diate lines on the hind wings are not zigzag and often coalesce. 
The life history of this species is similar to that of its northern 
relative. In Kentucky and Tennessee, the moths begin to 
emerge from over-wintered pupiB about the first of June and 
continue to emerge over a long period, until the latter part of 
August in some years. The oblique bands on the side of the cat- 
erpillar extend higher up on the back and are not V-shaped. The 
horn is usually strongly curved and reddish in color. The tongue- 
case of the pupa is somewhat shorter than in the northern species. 

Control. 

The presence of tomato worms is readily detected by the 
defoliation of the vine and by the droppings of the caterpillars 



172 MANUAL OF VEGETABLE-GARDEN INSECTS 

on the ground, although it is not easy to see the caterpillar 
itself as it rests motionless on a stem, its colors blending with 
the green of the foliage and the light stripes on its side suggesting 
the veins on the underside of the leaves. In the small garden 
or in larger fields where the caterpillars are not numerous, 
hand-picking is the cheapest and most practical means of 
control. When the worms appear in considerable abundance, 
spraying with paris green or arsenate of lead will give good 
results. Arsenate of lead is to be preferred on tomatoes because 
it is not so likely to burn the foliage. It is usually used at the 
rate of 2 or 3 pounds of the paste to 50 gallons of water. The 
first application should be made while the caterpillars are still 
small because they are then killed more quickly and by a smaller 
quantity of the poison than later. There is no danger in 
spraying tomatoes until the fruit is half grown, and some 
growers apply paris green till within ten days of picking. The 
arsenate of lead may be applied in the form of a dust diluted 
with some inert material. 

References 

Ky. Agr. Exp. Sta. Bull. GG, pp. 6-32. 1897. 
U. S. Farm. Bull. 120, pp. 10-14. 1900. 

The Tomato Stilt-Bug 

Jalysus spinosus Say 

The tomato stilt-bug is generally distributed throughout 
the United States and Canada east of the 100th meridian and 
has been reported as injurious to tomato in Missouri. The 
adult (Fig. 98) is a slender, elongate, brownish bug with long, 
delicate, thread-like legs and antennae. The last joint of the 
•antenna is enlarged and black. The insects are found on low 
vegetation in woods and fields. 

The female attaches her eggs singly to the stems of tomato 
plants. The egg is ^ inch in length, cylindrical, rounded 



TOMATO INSECTS 



173 



at each end, whitish to pale brownish in color and faintly ridged 
lengthwise. The eggs hatch in about five days. The nymphs 
are brownish green with the legs dark. In feeding, the bugs 
puncture the stems, the 
blossom stems, the ova- 
ries and the young fruits, 
causing the blossoms and 
fruit to fall. There are 
supposed to be at least 
three generations an- 
nually in southern Mis- 
souri. 

The bugs may be 
killed by spraying with 

u r^^ 1 ' T (• "^ ^rM) , FiG. 98. — Tho tonuito stilt-bug ( X 4) . 

lilack Leaf 40 to- 
bacco extract, 1 part in 800 parts of water to which enough 
soap has been added to make a suds. The insects are more 
easily hit in the early morning or late in the afternoon. 




Reference 
Mo. Fruit. Exp. Sta. Bull. 24, pp. 16-17. 1914. 



Fig. 99. — The 
tomato wire- 
worm ( X 3). 




Fig. lOU. — Adult of the 
tomato wireworni (X 4). 



The E.\stern Field 

WiREWORM 

Limonius agonus Say 

In New York, young 
tomato plants are 
sometimes seriously 
injured by a wireworm 
that bores up through 
the stem, causing them 
to wilt and die. This 
wireworm (Fig. 99) is 



174 MANUAL OF VEGETABLE-GARDEN INSECTS 

over ^ inch in length and reddish brown in color. The parent 
beetle (Fig. 100) is f inch in length, with the head and prothorax 
black, the legs brownish and the wing-covers reddish brown. 
The life history of the species has not been fully worked out. 

Injury may be avoided by not planting tomatoes on land that 
was in sod or corn the previous year. 

The Erinose of the Tomato 

Eriophyes cladophthirus Nalepa^ 

In Florida, Georgia and South Carolina, tomatoes are some- 
times infested by a minute mite which attacks the growing tips 
and the blossom buds. The feeding of the mites causes an 
irritation of the tissue, inducing the plant to send out a dense 
growth of white hairs, giving it the appearance of being covered 
with a white mold. It is under the protection of this dense 
growth of plant-hairs that the mites live, lay their eggs and 
feed. Growth is stopped and the buds do not set fruit. The 
life history and habits of this mite have not been carefully 
studied. The adult is elongate, vermiform and nearly color- 
less. It is provided with two pairs of legs and the abdomen is 
transversely striate and apparently divided into about seventy 
narrow rings. The female mite is about 3^ inch in length and 
the male about ■^^. 

The erinose of the tomato may be controlled by spraying 
the plants with the soda sulfur spray commonly used against 
mites on citrus. The formula for this mixture is : 

1 The identity of this mite is somewhat uncertain. Rolfs (Fla. 
Agr. Exp. Sta. Bull. 47, p. 143, 1898) referred the species to Phytopius 
calcladophora Nalepa, stating that the mite occurs in southern Europe. 
We have been unable to find any such species described by Nalepa. 
Apparently the P. calcladophora used by Rolfs is a misprint for Phtjtop- 
tns {Eriophyes) cladophthirus Nalepa. The latter was described from 
bittersweet (Solarium Dulcamara) in France, on which it produced 
erinea. Kirchner states that it produces a similar condition on tomato 
in Europe. 



TOMATO INSECTS 175 

Caustic soda (98 per cent) 10 pounds 

F'lowers of sulfur 20 pounds 

Water 20 gallons 

Mix the sulfur in cold water to a thick paste, add the soda and 
as it boils add water gradually to make 20 gallons. The water 
should be added fast enough to prevent burning, but not fast 
enough to stop boiling. The result will be a dark coffee- 
colored liquid. Strain through a fine-meshed cloth or spray- 
strainer. Keep in tightly-corked jugs. For use, mix one half 
gallon of this stock solution in 40 gallons of water. 

Dusting the plants with finely ground sulfur has also been 
found of benefit. 

Other Tomato Insects 

Corn ear-worm : 211 

Southern corn root-worm : 222 

Stink-bugs : 232 

Cabbage looper : 8 

Garden web worm : 18 

Harlequin cabbage bug : 38 

Green soldier-bug : 42 

Nezara viridula : 43 

Spinach aphis : 150 

Belted cucumber beetle : 11.5 

Southern leaf-footed plant-bug : 121 

Northern leaf -footed plant-bug : 122 

Garden springtail : 139 

Colorado potato beetle : 142 

Three-lined potato beetle : 149 

Potato aphis : 150 

Potato stalk-weevil : 155 

Common stalk-borer : 157 

Burdock borer : 160 

Potato tuber moth : 1G2 

Bean thrips : 69 

Garden flea-hopper : 77 

Spotted cutworm : 262 

Greasy cutworm : 265 

Dark-sided cutworm : 268 

Striped cutworm : 270 

Dingy cutworm : 271 



176 MANUAL OF VEGETABLE-GARDEN INSECTS 

Granulated cutworm : 273 
Clay-backed cutworm : 274 
Variegated cutworm : 27G 
Army cutworm : 287 
Fall army-worm : 292 
Yellow striped army- worm : 295 
Semi-tropical army-worm : 294 
Striped blister-beetle : 302 
Margined blister-beetle : 305 
Ash-gray blister-beetle : 30G 
Black blister-beetle : 307 
Two-spotted blister-beetle : 309 
Immaculate blister-beetle : 310 
Potato flea-beetle : 314 
Western potato flea-beetle : 318 
Tobacco flea-beetle : 319 
Pale-striped flea-beetle : 321 
Striped cabbage flea-beetle : 324 
Hop flea-beetle : 335 
Root-knot nematode : 338 
Millipedes: 342 
. Slugs: 354 
Red-spider : 351 



CHAPTER VIII 
EGGPLANT INSECTS 

The eggplant is subject to attack by most of the insects 
affecting the potato and tomato. Several species of flea- 
beetles attack eggplant and often cause serious injury, especially 
to the young plants. They are treated in C'hapter XVII. 

The Eggplant Tortoise Beetle 

Cassida pallidula Boheman 

In the southern states, the eggplant is occasionally subject 
to injury by the larvse and adults of a beautiful green or greenish 
yellow tortoise beetle about ^ inch in length. This beetle is 
distributed throughout the southern United States from Mary- 
land to Indiana and Kansas southward to Louisiana and west- 
ward to southern California. It feeds on eggplant, potato and 
horse-nettle and in California on nightshade. The beetles 
deposit their eggs singly or in groups of two to four, usually 
on the underside of the leaves. The egg is about ^ inch in 
length, elongate oval and brownish in color. It is covered 
and fastened to the leaf with a transparent brownish substance 
which is usually composed of two layers. Each female is 
capable of laying 250 eggs or more. The eggs hatch in four 
days to two weeks and the young larva is greenish white with 
the head dirty brown. The body is armed on each side with 
sixteen branched spines and on the back near the hind end of 
the body two long spines arise and extend forward. On this 
fork the insect carries its cast skins and excrement, using this 
N 177 



178 MANUAL OF VEGETABLE-GARDEN INSECTS 

load as a kind of sunshade. The larva passes through five 
stages and reaches maturity in twelve to twenty days. Pupa- 
tion takes place on the leaf, to which the pupa is attached by 
the hind end of the body and in two to ten days transformation 
to the beetle occurs. In Louisiana there are four or five 
generations annually. Both the larvae and adults eat out round 
holes in the leaves and often seriously injure young eggplants. 
The eggplant tortoise beetle rarely becomes sufficiently 
abundant to require remedial treatment but may be readily 
controlled by spraying with arsenate of lead (paste), 2 or 3 
pounds in 50 gallons of water. 

Reference 
U. S. Dept. Agr. Bull. 422. 1916. 

The Eggplant Lace-Bug 

Gargaphia solani Heidemann 

Throughout the southern states from Virginia, Missouri 
and Oklahoma southward, the eggplant is sometimes injured 
by a grayish or light brownish lace-bug. This insect is a 
native of America and fed originally on horse-nettle. It some- 
times occurs in great abundance on potatoes. 

The adult lace-bug is about ^ inch in length, flat, and under 
a lens presents a striking appearance. The prothorax is de- 
veloped into a hood that extends backward between the wings 
at the base, and its sides are expanded angularly. The front 
wings are broad, rounded at the tip, blackish at the base and 
apex, with a pale band across the middle and with the, veins 
arranged so as to form a beautiful reticulated network, resem- 
bling lace. The expanded margin of the prothorax is similarly 
reticulated. 

The female deposits her eggs on the underside of the leaves 
in circular clusters of 100 to nearly 200. The eggs are placed 



EGGPLANT INSECTS 179 

on end and lean in different directions. The mass is then 
covered with a protective secretion. The egg is bottle-shaped, 
greenish at the base and brownish towards the tip and about Cl- 
inch in length ; the top is crater-like with a white lace-like 
border. The eggs hatch in fivie to nine days. In feeding, the 
nymphs insert the bristles of the beak into the leaf and suck 
out the juices. The mother lace-bug watches over her egg-mass 
until the young are hatched and then cares for the nymphs 
until they have reached a considerable size. A small area 
surrounding an egg-mass is killed and the feeding of the nymphs 
enlarges the injured part. The colony of nymphs then migrates 
to a new position and there repeats the process. When abun- 
dant, the whole plant may be killed or so injured that a crop of 
fruit is not produced. In the course of its development, the 
nymph sheds its skin five times, acquiring wings at the last 
molt. About ten days are required for the nymphs to reach 
maturity. The fifth stage nymph is yellowish in color with 
a dark spot at the tip of the abdomen and is armed with numer- 
ous spiny processes. In Tidewater, Virginia, there are six gen- 
erations produced on eggplant and after this crop is harvested 
two or more generations develop on horse-nettle. 

Both nymphs and adults can be killed by spraying with 7 
or 8 pounds of whale-oil soap in 50 gallons of water. 

Reference 
U. S. Dept. Agr. Bull. 239. 1915. 

Other Eggplant Insects 

Corn ear-worm : 211 
Southern corn root-worm : 222 
Garden web worm : 18 
Harlequin cabbage bug: 38 
Green soldier-bug : 42 
Yellow bear caterpillar : 357 
Spinach aphis : 150 
Tomato worms : 168 



180 MANUAL OF VEGETABLE-GARDEN INSECTS 

Belted cucumber beetle : 115 
Southern leaf-footed plant-bug : 121 
Melon aphis : 135 
Colorado potato beetle : 142 
Potato aphis : 150 
Potato stalk- weevil : 142 
Common stalk-borer : 157 
Potato tuber moth : 162 
Garden flea-hopper : 77 
Greasy cutworm : 265 
Semi-tropical army-worm : 297 
Striped blister-beetle : 302 
Potato flea-beetle : 314 
Western potato flea-beetle : 318 
Tobacco flea-beetle : 319 
Eggplant flea-beetle : 320 
Pale-striped flea-beetle : 321 
Root-knot nematode : 338 
Red-spider : 351 



CHAPTER IX 

INSECTS INJURIOUS TO CARROT, CELERY, PARSNIP 
AND RELATED CROPS 

As a rule, these plants are relatively free from insect attack, 
but the carrot rust-fly, recently introduced from Europe and 
now gradually spreading over Canada and the northern states, 
promises to become a serious pest. 



The Carrot Rust-Fly 
Psila rosce Fabrieius 

The carrot rust-fly is a native of Europe, where it has been 
known since 1794. It was introduced into Canada probably 
in the early eighties, but 
first attracted attention 
at Ottawa in 1885. It 
soon became abundant 
in Quebec, New Bruns- 
wick and Nova Scotia. 
In New York it was 
first observed in Fulton 
County in 1901 . It now 
occurs in the northern 
states from Maine to 
Michigan. It is a serious 




Fig. 101. — The carrot rust-fly ( X 7§). 



enemy of carrots and celery and also attacks parsnips, parsley, 
celeriac and wild carrot. 

181 



182 MANUAL OF VEGETABLE-GARDEN INSECTS 



The parent insect (Fig. 101) is a small two-winged fly about 
^ inch in length. The body is shining dark green ; the head 
yellowish with the eyes red. The legs are pale yellowish. In 
New York the flies usually make their appear- 
ance some time in May, depending on weather 
conditions. Observation of the flies confined 
in cages has shown that they feed for about 
five days before they are ready to begin egg- 
laying. In the field they doubtless subsist on 
such drops of liquid as they may find. The 
Fig. 102. — Egg of mouth-parts are somewhat similar to those 
the carrot rust- ^£ ^^le house fiy, that is, thev are developed 

fly ( X 26). . - . ' . ^. 

into a fleshy, tongue-like organ with which 
the insect is able to lick or lap up liquids. 

The female fly has the tip of the abdomen provided with a 
sharp, extensile ovipositor by means of which she is able to 
tuck her eggs into crevices of 
the soil around the plant. Some 
of the eggs are laid between the 
base of the plant and the soil 
but many are found scattered 
about on the surface of the ground 
near the plant ; others are attached 
to the plant itself. Females have 
also been observed depositing eggs 
in cracks at some little distance 
from the plant. The egg (Fig. 
102) is about -^ inch in length 
and about ^ as wide as long. 
It is elongate oval, white in color 
and under the microscope shows 
a most beautiful sculptured pattern of delicate ridges and 
pits. Eggs have been found in abundance the last of May. 
The eggs hatch in about a week and the young maggot 




Fig. 103. — Young carrots in- 
jured by rust-fly maggots. 



INJURIOUS TO CARROT AND RELATED CROPS 183 

works its way down along the root and at first feeds on the 
tender tip. 

In the case of carrots and parsnips, the maggots at first feed 
on the tip of the tap-root and later the whole root is riddled 
with burrows which run in every direction. These burrows 
are of a rusty color, hence the common name of the insect. 
When badly infested, the carrot roots decay and when one 




Fig. 104. — Two celery plants injured by the carrot rust-fly and an unin- 
jured plant of the same age. 

attempts to pull them the lower part will break off and remain 
in the ground (Fig. 103). The outer leaves of infested plants 
soon turn yellowish and the whole top may wilt down and die. 
The injury to celery is of a somewhat different nature. 
Here the fibrous roots are eaten ofl' and destroyed. Infested 
plants take on a sickly whitish color and remain stunted. The 
plants are often able to throw out a new set of fibrous roots 
near the surface of the ground and can thus outgrow the injury 



184 MANUAL OF VEGETABLE-GARDEN INSECTS 



Fig. 105. 



in a measure, but the 
size and quality of the 

Larva of the carrot rust-fly (X7D. ^rop are seriousl.v im- 




Fig. 106. — Puparium of the carrot 
rust-fly (X 91). 



paired. In Fig. 104 are 
shown two injured plants in comparison with a healthy one. 
The maggots become mature in about a month. When full- 
grown the larva is about y^ 
inch in length, pale straw- 
colored, pointed in front with 
the posterior end of the 
body obliquely truncate. The 
mouth is provided with a pair 
of black, curved hooks with which the maggot is able to rasp 
off portions of the tissue of the root (Fig. 105). 

When mature, the greater number of the larvse desert the 
roots and in the surrounding soil trans- 
form to puparia. The puparium (Fig. 
106) is about ^ inch in length, light 
brownish in color and in shape re- 
sembles somewhat a grain of wheat. 
From these puparia there emerges in 
late August a second brood of flies. 
The insects hibernate as puparia 
in the soil or as maggots in the 
roots. 

It is quite probable that not all 
the puparia of the first brood trans- 
form the same season, but the second 
brood of flies is often large enough to 
produce a serious infestation of late 
carrots and to cause appreciable, 
injury to celery in the fall. While 

Fig. 107 - A celery root in- ^^^ maggotS of the SCCOnd brOod 
jured by rust-fly maggots • i e ^ ^ 

of the second brood. burrow in the tap-root oi the celery 




INJURIOUS TO CARROT AND RELATED CROPS 185 

plant, they very rarely ascend so as to enter the base of 
the leaves (Fig. 107). 

Unfortunately no method of controlling this pest has been 
devised applicable to the conditions under which its food plants 
are grown in this country. 



References 

U. S. Div. Ent. Bull. 3.3, pp. 26-32. 1902. 
Felt, 18th Rept. N. Y. State Ent., pp. 99-103. 



1903. 



The Carrot Beetle 

Ligyrus gibbosus DeGeer 

Throughout the United States, except in the extreme North, 
the roots of carrot, parsnip and celery are sometimes seriously 
injured by a medium-sized reddish brown 
insect which has much the appearance 
of a small June beetle. It is from ^ to 
f inch in length. On the front part of 
the thorax is a depressed area, in front 
of which is a small distinct tubercle 
(Fig. 108). The beetles feed mostly 
underground, gnawing out holes in the 
roots and underground stems. In 
addition to the plants mentioned above, 
the beetles have been known to attack 
beet, celery, sweet potato, potato, corn, 
dahlia, cabbage, sunflower and cotton, and among weeds 
ragweed and red-root. 

The beetles hibernate in the soil at a depth of six inches to 
four feet and are found in the field in greater or less abundance 
throughout the growing season. The eggs are laid in the soil. 
They are similar to those of the June beetles, white, smooth 
and shining, nearly globular, grayish, and about yt ii^ch in 




Fig. lOS. — The carrot 
beetle (X 2\). 



186 MANUAL OF VEGETABLE-GARDEN INSECTS 

length when newly laid. They increase considerably in size 
before hatching, which takes place in one to three weeks. The 
larvse feed on the roots of grasses and decaying vegetable matter 
and sometimes attack the same plants as do the beetles. When 
mature, the larva is 1^^ inches in length, bluish white with the 
head brown. From six to eleven weeks are spent in the larval 
stage. The mature grubs construct earthen cells within 
which to pupate and the beetles emerge two or three weeks later. 
There is apparently only one generation annually. 

The measures suggested for the control of the carrot beetle 
are of little practical value. Clean farming and a short rota- 
tion of crops will under ordinary conditions prevent serious loss. 

References 

U. S. Div. Ent. Bull. 33, pp. 32-37. 1902. 
Hayes, Jour. Ec. Ent., 10, pp. 253-261. 1917. 



The Black Swallow-Tail Butterfly 

Papilio polyxenes Fabricius 

The caterpillar of this large black and yellow butterfly feeds 
the leaves of celery, parsnip, carrot, parsley, caraway, 

fennel, sweet-fennel, dill, 
anise and nearly all wild 
umbelliferous plants. It is 
most destructive to young 
celery. The butterfly ranges 
throughout North America 
from southern Canada 
stmthward through Central 
America and the West 
Indies to Venezuela. 
The butterfl>' (Fig. 109) 
, , , , „ ^ ., has an expanse of 3-^ 

Fig. 109. — The black swallow-tail / • i mi. 

butterfly (x^). to nearly 4 mches. Ihe 




INJURIOUS TO CARROT AND RELATED CROPS 187 




Fig. 110. — Eggs of the black swallow-tail butterfly (X 12). 



male is somewhat 
smaller. The wings 
are black with two 
rows of yellow spots 
crossing both wings 
with a marginal row of 
yellow lunules. Be- 
tween the rows of yel- 
low spots on the hind 
wing and on the hind 
part of the front wing 
is a bluish band. On 
the posterior angle of 
the hind wing is an 
orange spot with a black 
center. In the male the 
yellow markings are 




Fig. 111. — The black swallow-tail butterfly, 
a young caterpillar and one nearly full- 
grown with the osmateria protruded ( X |) . 



188 MANUAL OF VEGETABLE-GARDEN INSECTS 




Fig. 112. — Caterpillar of the black swallow- 
tail butterfly suspended for pupation 
(X f). 



more distinct and on the hind wing the inner row of 
spots is replaced by a broad yellow band. In the North the 
butterflies emerge from over-wintered pup?e in May and June 
and deposit their eggs singly on. the upper side of the leaves of 

the host plants. In 
Florida the butterflies 
hibernate. The egg (Fig. 
110) is globular, about 
-^ inch in diameter, pale 
honey-yellow when first 
laid, changing to reddish 
brown in parts. The 
eggs hatch in about ten 
days. In the first stage 
the caterpillar is about 
Y^ inch in length, black, 
banded about the middle 
and rear end with white. When mature the caterpillar 
is about 2 inches in length, green, and each segment has a 
black band near the front margin inclosing six yellow spots. 
When disturbed this caterpillar has the habit of extruding a 
pair of orange-red horn-like 
scent organs from the dorsum 
of the prothorax (Fig. 111). 
These organs are known as 
osmateria and are probably 
for defense. The caterpillars 
become full-grown in three to 
four weeks and suspending 
themselves by a silken girdle 
(Fig. 112) transform to pupae on some nearby support. 
The pupa (Fig. 113) is 1-^ inches in length, light dirty 
brown marked with black and dark green. It is attached 
to its support by a button of silk at the hind end of the body 




Fig. 113. — Chrysalis of the black 
swallow-tail butterfly (X ft)- 



INJURIOUS TO CARROT AND RELATED CROPS 189 

and held in place by a silken girdle around the thorax. The 
pupal period lasts from nine to sixteen days. There are two 
broods in the North and at least three in the South. 

In California the black swallow-tail butterfly is replaced as a 
celery and parsley pest by a related species, Papilio zoHcaon 
Boisduval. 

Control. 

As this insect rarely becomes abundant, it may be usually 
held in check by hand-picking the caterpillars. 

Reference 
Scudder, Butterflies of Eastern U. S., 2, pp. 1353-1364. 1889. 



The Celery Leaf-Tyer 

Phlyctcenia ferrugalis Hiibner 

Celery is occasionally injured by a small greenish caterpillar 
that folds or webs together the leaves and sometimes bores 
down into the 
stalks. This in- 
sect is widely 
distributed in 
Europe, Asia and 
North America. 
In the United 
States it has 
been reported 
injuring celery, 
spinach and beet 
but is best known 
as a greenhouse 
pest, attacking a wide variety of hot-house plants. Its 
wild food plants include boneset, hedge nettle, strawberry 




Fig. 114. — The celery leaf-tyer, caterpillar (X 3i). 



190 MANUAL OF VEGETABLE-GARDEN INSECTS 




Fig. 115. — The celery leaf-tyer, pupa ( X 5). 



and burdock. The caterpillars have been occasionally found 
feeding on celery and beet in August and September. 

The full-grown 
caterpillar (Fig. 
114) is f inch 
in length, trans- 
lucent greenish 
white with a pair 
of black spots on 
the cervical shield. The body is marked with a dark green 
median stripe bordered by a much wider greenish white one. 
When disturbed the caterpillar has the habit of wriggling 
actively back and forth. The larva generally 
feeds openly on the under surface of the 
leaves, but sometimes it forms a retreat by 
webbing together several leaves loosely with 
silk. Under greenhouse conditions, the cater- 
pillars mature in about three weeks. Pupa- 
tion takes place within thin white, silken 
cocoons spun within folded leaves. The 
pupa (Fig. 115) is a little less than ^ inch in 
length and dark brown or black. The pupal 
period varies from twelve to twenty days, 
the moth did not emerge until a year after the pupa was 
formed. The moth (Fig. 116) has an 
expanse of about ^ inch and is rusty 
brown with somewhat obscure blackish 
markings on the front wings. The 
flight of the moths is short and jerky and 
on alighting they quickly hide on the 
underside of the object. The small, flat, 
elliptical, translucent eggs (Fig. 117), 

Fig. 117. — Eggs of the ^^°"* '^ "^^^ "^ diameter, are deposited 
celery leaf-tyer (X22). on the underside of the leaves in small 





Fig. 116.— The cel- 
ery leaf-tyer 
moth (X 1|). 

In one instance 



INJURIOUS TO CARROT AND RELATED CROPS 191 

clusters of two to twelve, often overlapping. The eggs hatch 
in twelve to fourteen days. Under greenhouse conditions, there 
are from seven to eight generations annually ; in the open there 
are said to be only four. 

The celery leaf-tyer has never been found causing serious 
injury in the open and no methods of controlling it under such 
conditions have been devised. 

References 

Buckler, Ent. Mo. Mag., 14, pp. 200-204. 1878. 
Fletcher and Gibson, Can. Ent., 33, pp. 140-144. 1901. 
Cornell Agr. Exp. Sta. Bull. 190, pp. 159-164. 1901. 

The Celery Looper 

Autographa falcigera Kirby 

Throughout the United States and southern Canada east of 
the Rocky Mountains, celery, lettuce and sugar-beets are some- 
times subject to the attack of a looping caterpillar. These 
caterpillars hibernate in a partly grown condition and com- 
plete their development in early spring. The full-grown larva 
is \^ inches in length, pale translucent green in color, and 
marked with a median dark line, on each side of which are 
three light lines. The stigmatal stripe is white bordered 
above by a dark green stripe. The spiracles are white, dis- 
tinctly ringed with black, a character by which it may be dis- 
tinguished from the cabbage looper. The body becomes 
gradually larger towards the posterior end, which is obliquely 
truncate. Although these caterpillars are closely related to 
the cutworms, they crawl with a peculiar looping motion owing 
to the absence of prolegs on the third and fourth abdominal 
segments. In Illinois the over-wintered caterpillars become 
mature in late April and pupate in silken cocoons. The pupal 
period occupies nine or ten days. 



192 MANUAL OF VEGETABLE-GARDEN INSECTS 

The moth has an expanse of about 1^ niches. The front 
wings are purplish brown with an obHque band in the front 
angle and the area back of the silver spot velvety reddish brown. 
The silver mark is distinct and the hind margin of the front 
wing is scalloped so as to leave a rounded projection at the 

1 hind angle. The hind wings are 

■1 ^ - j^^^ yellowish brown, darker toward the 

^H|^^|gA|^^|^^H^ margin, which is edged with white 

. ^(^^Bfl||^^|r '^^^^ ^gg is about gV ^^ch in 

^^^ ^ ^^^ diameter, milky white, globular, 

slightly flattened and marked with 



Fig. 118. — Moth of the celery delicate longitudinal ridges. The 

looper (X U). I, ^ -u ' I. ^ i 

eggs hatch m about a week. 

In Illinois there are apparently three broods annually, the 
moths flying in April and early I\Iay, in late July and early 
August and again in late September. The caterpillars of the 
summer brood require about three weeks to reach maturity. 

The celery looper does not often occur in sufficient numbers 
to require remedial measures. As arsenicals cannot be used 
on celery or lettuce, hand-picking the caterpillars is the only 
measure available and will usually be found sufficient. 

Reference 
Coquillett, 11th Rept. State Ent. 111., pp. 38-43. 1882. 

The Tarnished Plant-Bug 

Lygus pratensis Linnaeus 

The tarnished plant-bug is one of the commonest insects 
found on garden plants. It feeds on a great variety of trees, 
shrubs and herbs, showing a special liking for opening buds, 
flowers and tender new growth. It is widely distributed through- 
out the entu*e north temperate zone. The adult (Fig. 119) is an 



INJURIOUS TO CARROT AND RELATED CROPS 193 




Fig. 119. — The tarnished 
plant-bug, adult ( X 4|). 



inconspicuous, brownish bug mottled with various shades of 
reddish and yellowish brown, ^ to ^ inch in length. The bugs 
are shy, taking flight at the slightest alarm, and are often over- 
looked by the gardener. 

This insect hibernates as an adult in leaves, grass, stone 
piles and under other rubbish. The 
bugs emerge in early spring and are 
then often destructive to the buds of 
fruit-trees and nursery stock. They 
are also to be found abundantly in 
mullein rosettes and as soon as the 
days become warmer they begin 
feeding on various weeds. In New 
York the eggs become mature in the 
over-wintering females by the last 
of April or the first cf iNIay and a 
generation of young is produced, 
giving rise to a new brood of adults the latter part of June. 
The egg (Fig. 120) is nearly ^ inch in length, flask-shaped 
and obliquely truncate at the anterior end. The eggs are in- 
serted their full length into the tender tissue of the plant. 

They have been found in the petioles 
of peach leaves, the blossom buds of 
dahlias, the seed-stalks, stems and 
leaves of volunteer turnips and later 
in the season in the heads of com- 
posite plants such as daisies and 
asters. They hatch in about ten 
days. The nymphs are yellowish 
green to greenish, marked on the 
thorax with four black spots. In the older nymphs the 
thorax and wing-pads are variously mottled with brownish 
(Fig. 121). In late summer and fall the nymphs are very 
abundant on wild carrot, goldenrod and wild asters. There 




Fig. 120. — Eggs of the tar- 
nished plant-bug in position 
in tender peach tip (X 11). 



194 MANUAL OF VEGETABLE-GARDEN INSECTS 




Fig. 121. — The tar- 
nished phint-bug, 
fifth stage nymph 

of the 
plant attacked. In the 
case of potatoes, the in- 
jury is similar to that 
produced by several other 
insects and is known as 
tip-burn. This is most 
serious in years of 
drought. The bugs 
sometimes puncture bean 
pods, arresting growth at 
the point of injury. In 
the case of beets the 
punctures cause a curling 
or kinking of the leaves 
(Fig. 122) and in severe 
cases a stunting of the 
plants. The bugs often 
attack celery plants that 



are five nymphal stages, the insect becom- 
ing mature at the fifth molt. The life cycle 
requires from twenty-five to thirty days, 
and there are probably four or five genera- 
tions annually. 

Most of the injury to cultivated plants 
is caused by the feeding punctures of the 
adults, since most of the nymphs are to be 
found on weeds. In feeding, the bug 
punctures the plant with the sharp needle- 
like bristles of its beak and sucks out the 
juices, at the same time apparently inject- 
ing some substance poisonous to the tissue. 
The character of the injury varies with the 
nature 




Fig. 122. — Beet leaf kinked by the tarnished 
plant-bug. 



INJURIOUS TO CARROT AND RELATED CROPS 195 




Fi(i. 12.3. — Ad( I phocoris 
rapidus, adult (X 5j). 



are blanching, puncture the tender stalks, producing large 
brown wilted spots and a blackening of the tissue at the joint. 
This trouble is known among celery-growers as black joint. 
The injury mars the appearance of 
the plants, lessens their market value 
and causes considerable loss. Cab- 
bage, cauliflower, turnip, salsify and 
cucumber are also subject to attack, 
but serious injury to these plants is of 
rare occurrence. 

It is rarely possible to prevent attack 
by the tarnished plant-bug because the 
injury is inflicted by the adults that 
have developed on wild plants, 
common weeds that are everywhere 
present. They are too active to be hit by a spray and so 
resistant to insecticides that it is impossible to kill them with- 
out using some material that would injure the plants. Clean 
farming is often recommended as a means of reducing the 
numbers of the bugs, but under 
circumstances gives little 
relief. 

Another plant-bug, 
Adclphncoris rajjidiis 
Say, is often associated 
with the tarnished 
plant-bug, feeding on 
potato, sugar-beets, cel- 
ery and cotton. It 

also feeds on numerous Fig. 125. — Add phocoris mpi- 

weeds and is sometimes ^"*' ^^*^ '^'^^^ ""^'"^^^ ^^ ^^• 
injurious to the fruit of the strawberry. The adult (Fig. 123) 
is a little over -^ inch in length. The head, legs and prothorax 
are yellow ; there are two black spots near the hind margin of 




Fig. 124. — Egg 
of Adelphocoris 
rapidus (X 23). 




196 MANUAL OF VEGETABLE-GARDEN INSECTS 



the prothorax and the wings are dark brown except the edge, 

which is narrowly bordered with yellowish. The* antennae 

are black, broadly ringed wdth yellowish white. 

The life history is similar to that of the tarnished plant-bug 

and the eggs are deposited in similar places. The egg is also 

similar but bears a small spine at the edge of the cap (Fig. 124). 

The insect passes through five nymphal stages. The nymphs 

are gayly colored with green, red and various shades of brown 

(Fig. 125) and are found abundantly throughout the growing 

season. 

Reference 

Cornell Agr. Exp. Sta. Bull. 346. 1914. 

The Negro-Bug 

Thyreocoris pulicarius Germar 

A serious outbreak of this small black stink-bug occurred in 
the celery fields of Michigan in 1893, causing a loss of many 
thousand dollars. A similar outbreak took place in northern 

Ohio in 1906. It is surprising that 
attacks of this kind have not been 
more frequent, since the bugs are 
often abundant on their wild food 
plants over large areas every year. 
The insect ranges throughout the 
United States and Canada east of 
the Rocky Mountains southward to 
Florida and Arizona. The adult 
(Fig. 126) is about ^ inch in length, 
shining black, strongly convex, short 
and broad, widest on the thorax 
The scutellum is greatly developed 
and covers the abdomen; the exposed edge of the wing 
is yellowish white. 
The insect hibernates in the adult condition and the bugs 




Fig. 126. — The negro-bug, 
adult (X 14). 

and rounded behind. 



INJURIOUS TO CARROT AND RELATED CROPS 197 

appear on their food plants in the spring. In IlHnois the eggs 
are laid in May and June. They are deposited singly on the 
leaves. The egg is :^ inch in length, elongate, shining, light 
orange when first laid but deepening to bright red just before 
hatching. The egg has been observed to hatch in sixteen 
days. The older nymph is similar to the adult but has the 
abdomen blood-red. The nymphs become mature in July and 
the adults, after feeding for a few weeks, go into hibernation 
rather early. The insect breeds abundantly on various weeds, 
including beggar-ticks, tick-seed, red-root, ground-nut, great 
lobelia and neckweed (Veronica peregrinaf). It has also been 
found injurious to corn, wheat and grass and the bugs often 
give an unpleasant flavor to raspberries and strawberries. 
There is only one brood developed annually. 

The injury to celery has been caused almost entirely by the 
adults. They congregate in clusters at the base of the petioles 
on the highest stalks and suck out the sap, causing the leaves 
to wilt and die. Later they attack the lower leaves at the 
center of the plant. Celery so injured is stunted and the stalks 
more or less deformed, and much of it is rendered unsuitable for 
market. 

When infesting celery, the negro-bug can best be controlled 
by spraying with "Black Leaf 40" tobacco extract, 1 pint in 
100 gallons of water in which 5 to 6 pounds of soap have been 
dissolved. Much may be accomplished in preventing attack 
by keeping down all wild plants on which the insect may breed. 

Reference 
Mich. Agr. Exp. Sta. Bull. 102, pp. 13-18. 1893. 

The Parsnip Webworm 

Depressaria heracliana Linnaeus 

In growing parsnip and celery seed, much trouble is often 
experienced from the depredations of small greenish yellow 



198 MANUAL OF VEGETABLE-GARDEN INSECTS 

caterpillars that web together and devour the unfolding blossom 
heads. The insect is widely distributed in Europe and eastern 
North America. It feeds on wild parsnip, wild carrot and 
other umbelliferous plants. 

The insect hibernates in the adult stage. The small grayish 
moths are found under flakes of bark, in crevices, or in similar 
situations. The moth has an average expanse of about an 
inch. The front wings are brownish gray marked with inter- 
rupted longitudinal dark lines and a small black spot near the 
center. The hind wings are pearl-gray. Over-wintered speci- 
mens are usually much rubbed and are much lighter in appear- 
ance. The moths deposit their eggs singly in May, June and 
July on the leaves, stems and particularly on the sheath sur- 
rounding the flower-head. The egg is elongate, oval, pearly 
white, ribbed longitudinally, and about ^V inch in length. 
The eggs hatch in about seven days and the young caterpillars 
enter the flower-buds, where they feed, webbing them together 
with silk. When the flower-cluster opens, the caterpillars re- 
main in the protection of the web and continue to feed on the 
flowers and later on the seeds. They become full-grown in 
four to five weeks. The mature caterpillar is about f inch in 
length, greenish yellow above, lighter yellow on the sides and 
beneath. The head, cervical shield and thoracic legs are 
shiny black. The body is sparsely clothed with hairs arising 
from small black warts. 

When nearly mature, the caterpillars leave the flower-heads 
and burrow into the stems, usually in the axils of the leaves. 
After entering the stem, the caterpillar feeds for a short time 
and then constructs a slight cocoon of silk and excrement in 
which pupation takes place. The pupa is about ^ inch in 
length, with a dark brown thorax and light brown abdomen. 
The moths emerge in about three weeks and soon go into hiber- 
nation in sheltered places. 

No practical method of controlling this insect has been de- 



INJURIOUS TO CARROT AND RELATED CROPS 199 

vised. After the flower-heads have opened, many of the 
caterpiHars may be destroyed by spraying or dusting with an 
arsenical. 

References 

Riley, Insect Life, 1, pp. 94-98. 1888. 

Mich. Agr. Exp. Sta. 3rd Rept., pp. 112-115. 1890. 

Brittain and Gooderham, Can. Ent., 48, pp. 37-41. 1916. 

The Parsnip Leaf-Miner 

Acidin fr atria Loew 

Sometimes the leaves of parsnip are disfigured by the mines 
of a small whitish maggot. This insect is never very abundant 
but is widely distributed throughout the whole United States 
and is probably identical with the European celery fly, Aridia 
hcraclci Linnseus. The greenish translucent maggots are found 
in the leaves from May till July, where they produce blotch 
mines. Several larvae occupy the same leaf and the mines 
coalesce. The mines are most abundant on the lower leaves 
or on plants grown in partial shade. \Yhen mature, the maggots 
are a little over i inch in length. They transform to straw- 
colored puparia usually within the mine, and the flies emerge 
in about two weeks. The fly is about ^ inch in length. The 
head, thorax and legs are pale yellow and the abdomen green. 
The wings are beautifully marked with yellowish brown curved 
bands. The number of generations annually has not been 
definitely determined. 

Reference 

U. S. Bur. Ent. Bull. 82, pp. 9-13. 1909. 

The Parsley Stalk- Weevil 

Listronotus latiusculns Boheman 

This insect has been recorded as injuring parsley planted on 
low land in Virginia and in coldframes in Connecticut. The 



200 MANUAL OF VEGETABLE-GARDEN INSECTS 

larvae were found boring in the stems and roots, causing the 
death of the plant. This weevil breeds normally in the heads 
and stalks of the common arrowhead, a plant found growing in 
low, wet ground. Its attack on parsley was apparently more 
or less incidental. 

Other Carrot, Celery and Parsnip Insects 

Cabbage looper : 8 
Yellow bear caterpillar : 357 
Spinach aphis : 105 
Garden springtail : 139 
Bean aphis : 76 
Garden flea-hopper : 77 
Spotted cutworm : 262 
Striped cutworm : 270 
Variegated cutworm : 276 
Spotted-legged cutworm : 282 
Army cutworm : 287 
Army-worm : 288 
Striped blister-beetle : 302 
Black blister-beetle : 307 
Potato flea-beetle : 314 
Pale-striped flea-beetle : 321 
Root-knot nematode : 338 
Millipedes: 342 
Wheat wireworm : 348 
Slugs: 354 



CHAPTER X 



ASPARAGUS INSECTS 



The important insects infesting asparagus arc relatively few 
in number, and, like their host plant, are of European origin. 



The Common Asparagus Beetle 

Crioceris asparagi Linnaeus 

This common beetle is a native of Europe and was first found 
in this country at Astoria on Long Island in 18G0, although it 
had probably been present in that locality for several years. 
The insect has gradually extended its 
range until it is now widely distributed 
from North Carolina to Massachusetts 
and Canada and westward to Illinois. It 
was introduced into California about 1904 
and is now widely spread throughout the 
central part of the state. It has also 
been reported from Colorado. 

The asparagus beetle (Fig. 127) is 
about -J inch in length. The head, under 
parts, legs and antenna? are bluish black 
frequently tinged with green. The tibiae 
are reddish at base. The thorax is 
reddish usually with two black spots near 
the center. The markings on the wing- 

201 




Fig. 127. — The com- 
mon asparagus beetle 
(X5). 



202 MANUAL OF VEGETABLE-GARDEN INSECTS 




covers vary greatly even in specimens from the same locality. 
The inner margin of each wing-cover is bluish black ; the 
outer margin and the tip are orange. The intervening space 
is yellowish white broken into three spots by bluish black 
bands which are usually connected with the inner marginal 

stripe. In some cases 
these bands are 
broken into spots. 
Sometimes the two 
wing-covers on the 
same insect are not 
marked alike. Varia- 

FiG. 128. — Diagram to show variations in the tions in the pattern 
pattern on the wing-covers of the common aspar- , . ,-,. 

agus beetle. are shown m Fig. 

128. There is a 
tendency in the South for the beetles to be lighter in color. 

The beetles pass the winter under any convenient shelter 
such as piles of rubbish, under the bark of trees or in similar 
situations. They have often been found in great numbers in 
heaps of old asparagus roots where the field has been plowed up. 
The beetles emerge from their winter quarters at the time 
the young shoots are just coming up. They attack the tender 
tips, eating out holes 
and producing a 
brownish discolora- 
tion of the tissue. 
When abundant the 
crop may be seriously 
damaged. The beetles soon begin to lay their eggs on the young 
shoots. The egg (Fig. 129) is elongate oval, blackish brown and 
about ^ inch in length. The eggs are laid on end singly or 
in rows from two to eight. Early in the season they are laid 
on the tips, but later are attached to the leaves and flower- 
stems. The eggs hatch in three to eight days and the young 




Fig. 129. — Eggs of the common asparagus 
beetle (X 6). 



ASPARAGUS INSECTS 



203 



grubs begin feeding on the tender tips. The body of the newly 
hatched larva is gray and its head and legs are black. The 
grub becomes mature in ten days to two weeks. It is then 
about yV i"t'h in length, dark gray in color, with the head and 
legs shining black. On the segment behind the head there 
are two shining black spots. The abdominal segments are 
provided with prolegs which are used by the grub in maintain- 
ing its hold on the plant (Fig. 130). When mature the grubs 
fall to the ground and there just below the surface construct a 
small earthen cell within which they transform to pale yellow- 
ish pupae. Transformation to the beetles takes place in about 
a week, although in 
cool weather the pupal 
period may be much 
longer. In England 
the insect remains in 
the pupal state from 
fourteen to twenty 
days. After trans- 
formation the beetles 
require three or four 

days to harden before they are ready to make their appear- 
ance above ground. The entire life cycle requires from three 
to seven weeks depending on the climate. In the North 
there are at least two generations annually and in the South 
there are said to be four or five. 

In addition to the injury to the tender shoots in the spring, 
the beetles and larva^ seriously damage the plants after they 
have leafed out. Both beetles and grubs feed on the leaves 
and the epidermis is chewed from the stem. In this way the 
growth of the plants is seriously checked and the proper develop- 
ment of the roots is prevented. Plants stunted in this way 
are not able to send up large and vigorous shoots, and the size 
and quality of the crop are decreased. The common asparagus 




Fig. 130. — Full-grown larva of the common 
a.sparagus beetle (X 4j). 



204 MANUAL OF VEGETABLE-GARDEN INSECTS 

beetle is very troublesome in newly set beds. Frequent de- 
foliation weakens the plants, making it difficult for them to 
become established. 

The common asparagus beetle is held in check by a small 
Chalcid parasite, Tetrastichus asparagi Crawford, the life his- 
tory of which is remarkable. The adult parasite appears in 
the asparagus field in the spring while the eggs of the beetle 
are being laid. The female inserts her eggs in those of the 
beetle. The beetle egg hatches and its larva, containing the 
larvae of the parasite, reaches maturity, enters the ground and 
constructs its pupal cell but does not pupate. The parasites 
then complete the destruction of the host and emerge from its 
shriveled remains, pupate within the cell constructed by the 
beetle larva and later emerge as adults. From one to ten para- 
sites have been reared from a single beetle larva. 

Methods of control. 

In asparagus fields in which the crop is being cut for market, 
the injury to the young shoots by the larNie may be prevented 
by cutting the crop clean every three to five days. In this way 
all the eggs deposited on the shoots will be removed before or 
very soon after hatching. All volunteer plants should be de- 
stroyed but it will often pay to leave a row here and there 
uncut to serve as a trap on which the beetles will congregate, 
feed and lay their eggs. Here they may be poisoned with 
arsenate of lead (paste), 1 pound in 20 gallons of water, or the 
plants may be cut and burned, thus destroying the early stages 
of the beetle. After the cutting season is over, the plants may 
be protected from beetle injury by two or three applications 
of arsenate of lead (paste), 1 pound in 20 gallons of water. It 
is not an easy matter, however, to spray thoroughly a large 
field of asparagus when the plants have made a heavy growth. 
In newly set beds, spraying with arsenate of lead is often re- 
sorted to with satisfactory results. In this case the application 



ASPARAGUS INSECTS 205 

should be made early in order to destroy the first brood of 
beetles and larvte and thus give the plants a chance to make a 
strong growth early in the season. 

The use of poultry for the destruction of the beetles was 
advised by T. W. Harris nearly eighty years ago. This method 
of control is still practiced with good results in some localities. 
The asparagus field is surrounded with a chicken-wire fence, 
and poultry are allowed the run of the field. Thirty or forty 
hens are sufficient to keep a two-acre field practically free from 
the beetles during the early part of the season. When the 
plants grow up, some of the beetles wall keep out of reach and 
they may become abundant in the fall. It is rarely necessary, 
however, to resort to spraying in fields in which poultry are 
allowed to run. In the home garden the larvse may be de- 
stroyed by dusting the plants with hydrated lime or land 
plaster. 

References 

Fitch, 8th Kept. State Ent. N. Y., pp. 177-186. 186.3. 

Lintner, 1st Kept. State Ent. N. Y., pp. 239-246. 1882. 

Board Agriculture [England] Leaflet 47. 1902. 

Chittenden, Yearbook U. S. Dept. Agr., pp. .341-349. 1896. 

Johnston, .Jour. Agr. Research, 4, pp. 303-314. 1915. Parasite. 

Sajo, Prometheus, 13, pp. 166-171. 1902. 

U. S. Farm. Bull. 837. 1917. 



The Twelve-Spotted Asparagus Beetle 

Crioceris duodecimpunctata Linnseus 

In this country, the twelve-spotted asparagus beetle (Fig. 
131) was first noticed in 1881 in ^laryland. It gradually 
spread northward, reaching New Jersey in 1892, New York in 
1893 and Canada in 1898. Its range now extends from Maine 
to the Niagara peninsula in Canada and southward to Virginia. 

This beetle is most injm'ious early in the season when the 



206 MANUAL OF VEGETABLE-GARDEN INSECTS 




adults attack the growing tips and sometimes eat the buds as 
soon as they appear above the ground. The beetles also feed 
on the foliage and eat out irregular areas in the bark of the 
stems. The larvae cause very little injury 
since they feed almost entirely inside the 
berries. 

The insect passes the winter in the 
adult condition, hidden away in dry, 
sheltered places. The beetles leave their 
winter quarters about a week later than 
the common asparagus beetle. They feed 
on the tender asparagus shoots in much 
the same way but do not deposit their 
eggs until about the time the plants 
begin to blossom or from three weeks to 
a month after appearing in the field. 

The twelve-spotted asparagus beetle is 
slightly larger and more robust than the 
other species. Its general color is reddish orange. The 
antennae, eyes, knees, tarsi and the underside of the thorax 
are black. On each wing-cover there are six distinct black 
spots. The eggs are deposited singly on the leaves of 
asparagus plants, usually those bearing fruit. The egg (Fig. 
132) is about -^ inch in length by -q\ inch in width and is 
pointedly rounded at each end. The surface is smooth, shin- 
ing and without apparent sculp- 
ture. When first laid, the egg is 
nearly white, changing through 
yellow or orange to light green or 
brownish olive. It is attached to 
the leaf by one side. The eggs hatch in a week to twelve 
days. The young larva is about -^ inch in length, pale 
yellow or orange in color, with the head, legs and a spot on 
each side of the first segment black. The young larva feeds 



Fig. 131. — The twelve- 
spotted asparagus 
beetle (X 5). 



Fig. 132. — Egg of the twelve- 
spotted asparagus beetle (X 12). 



I 



ASPARAGUS INSECTS 207 

very little if at all on the foliage but wanders about till it 
finds a berry, which it enters usually at the blossom end. 
The lar\-a feeds on the seeds and migrates from berry to 
berry until full-grown. Sometimes three or four berries are 
attacked by a single larva. In the course of its develop- 
ment, the larva passes through three stages. When full- 
grown it is about -j inch in length and varies in color from 
light orange to brownish yellow. The legs and two spots on 
the jjrothorax are black. The larva becomes mature in three 
to four weeks. It then descends to the ground, where just 
below the surface it spins a tough silken cocoon into which 
particles of dirt are incorporated. In about two days after 
building its cocoon, the larva transforms to a yellowish pupa 
and in twelve to sixteen days the transformation to the adult 
takes place. In New York the beetles of the second brood 
appear in July and lay eggs for a second generation. The 
beetles of the next brood emerge in August and September and 
go into hibernation with the advent of cold weather. There 
are two generations annually in the North. 

In Europe two other beetles attack asparagus, the fourteen- 
spotted and the five-spotted asparagus beetles {Crioceris qua- 
t iiordecimpunctata and C. quinquepunctata). The larvae of both 
species are said to feed on the foliage in much the same way 
as the larva of the common asparagus beetle. 

Methods of control. 

Since the larvae live inside the berries, they cannot be reached 
with an arsenical poison but the beetles may be killed by spray- 
ing with arsenate of lead as suggested for the control of the 
common asparagus beetle. 

References 

Lintner, 12th Kept. State Ent. N. Y., pp. 248-252. 1897. 
Sajo, Prometheus, 13, pp. 166-171. 1902. 
Cornell Agr. Exp. Sta. Bull. 331, pp. 422-435. 1913. 
U. S. Farm. Bull. 837. 1917. 



208 MANUAL OF VEGETABLE-GARDEN INSECTS 



The Asparagus Miner 

Agroinyza simplex Loew 
{Agromyza maura var. simplex Loew) 

In the present state of knowledge of this group of flies, it is 
impossible to indicate with any accuracy the geographical dis- 
tribution of this species. There are several closely related 
forms in the genus Agromyza considered as distinct species by 
some authors and as varieties of Agromyza maura Meigen by 
others. The asparagus miner belongs to this group. As the 
haljits and early stages of most of these varieties or species are 
still unknown and as it is very difficult to distinguish them 
from a study of the flies alone, it is at present impossible to 
determine the actual range of this pest. In America Agromyza 
simplex has been recorded from Massachusetts, Ontario and 
Illinois and southward to Georgia. It also occurs in central 

California. It has been 
reared in France and the 
flies have been captured 
in England and Germany. 
What is apparently the 
same species but deter- 
mined as Agromyza maura 
was reared from aspara- 
gus in Hungary. 

The adult of the aspara- 
gus miner (Fig. 133) is a 
small, metallic, black, 
two-winged fly, |^ to |^ 
inch in length and having an expanse of 3- to -j inch. In 
New York the flies appear from the middle to the last of 
May. In about a week after emerging, the female inserts 
her eggs just under the epidermis of the asparagus stalk near 




Fig. 133. — The asparagus miner, adult 

(XS). 



ASPARAGUS INSECTS 209 

the ground. The egg is elongate oval, slightly wider at one 
end and somewhat pointed at the other. It is about 5V 
inch in length and when first laid is glistening white in 
color. The eggs hatch in twelve to eighteen days and the 
young maggot begins to mine just under the epidermis. At 
first the larva works upward, following a more or less sinuate 
course, but when nearly mature it turns downward towards 
the base of the plant. In the case of the first brood, pupation 
may take place aboveground but the maggots of the second 
generation usually w'ork down from one to seven inches below 
the surface before transforming. The full-grown maggot is 
creamy white in color and is ^ to ^ inch in length. The maggots 
attain their growth in two or three weeks and transform into 
puparia within the mine. The puparium is ^ to ^ inch in length 
and brownish in color, becoming darker with age. The insect 
remains in this stage for two to three weeks and the flies of 
the second brood begin to emerge the latter part of July. The 
maggots of the second brood are most abundant in their mines 
during August but both maggots and flies are present until 
frost. The winter puparia are formed in late August and 
September. These are found under the epidermis of the 
stems below ground. There are two generations annually. 

When, as is often the case, several maggots infest a single 
stem, their mines cross each other, thus girdling the shoot. 
Stems injured in this way take on a sickly yellowish appearance 
and die prematurely, thus weakening the plants to a consider- 
able extent. 

Methods of control. 

The asparagus miner rarely does enough damage to warrant 
commercial growers making any serious efforts to control it, 
and no remedial measures satisfactory for commercial condi- 
tions have been devised. The insect causes little or no trouble 
in beds that are being cut, its injuries being chiefly confined to 



210 MANUAL OF VEGETABLE-GARDEN INSECTS 

new beds. It has been recommended to pull up and burn 
infested stalks in the fall after frost or in the spring and thus 
destroy the over-wintering puparia. This is a laborious opera- 
tion and, as many of the stems are broken off, enough puparia 
will be left to reinfest the field. It has also been suggested 
that the flies might be killed with a sweetened poison bait but 
as this method has not been tried under field conditions its 
value is very doubtful. 

References 

N. Y. (Geneva) Agr. Exp. Sta. Bull. 189. 1900. 

U. S. Bur. Ent. Circ. 135. 1911. 

Cornell Agr. E.xp. Sta. Bull. 331, pp. 411-421. 1913. 

Other Asparagus Insects 

Corn ear-worm : 211 
Southern corn root-worm : 222 
Stink-bugs: 232 
Cabbage looper : 8 
Harlequin cabbage bug : 38 
Yellow bear caterpillar : 357 
Belted cucumber beetle : 115 
Southern leaf-footed plant-bug : 121 
Melon aphis : 135 
Potato aphis : 150 
Bean aphis : 76 
Greasy cutworm : 265 
Black army-worm : 275 
Variegated cutworm : 276 
Yellow-striped army-worm : 295 
Root-knot nematode : 338 



CHAPTER XI 

CORN INSECTS 

The insects feeding on Indian corn are nnmerous, over two 
hundred species having been recorded as more or less injurious 
to some part of the plant. The roots are injured by wire worms, 
white grubs, corn root-worms, by the larvae of bill-bugs and are 
infested by the corn root-aphis. The young plants are fre- 
cjuently eaten off by cutworms, the leaves riddled by flea- 
beetles and the crown tunneled by the stalk-borers. The 
unripe ears are attacked by the ear-worm, which is the most 
important insect infesting sweet corn. In this chapter no 
attempt is made to give a comprehensive account of the insects 
injurious to field corn ; only the more important species are 
treated and only those most likely to attack sweet corn. 

The Corn Ear-Worm 

Heliothis obsoleta Fabricius 

The corn ear-worm ranges throughout the United States 
and southern Canada, southward through ^Mexico and the 
West Indies to Argentina. In the Old World it is found 
throughout Africa and Europe eastward to China, India, the 
East Indies, Australia and New Zealand. In the southern 
states, this insect is a serious enemy of cotton and is there known 
as the cotton boUworm. Corn is the favorite food plant of this 

211 



212 MANUAL OF VEGETABLE-GARDEN INSECTS 

insect, serious injury to this crop being of annual occurrence 
from the vicinity of New York City southward east of the 
Appalachian ^Mountains ; from Ohio, Illinois, Nebraska and 
Montana southward to the Gulf and in the warmer parts of 
the Far West. It occurs in the greatest abundance, however, 
and is most destructive in the cotton belt. From New Jersey 
southward, the corn ear-worm is considered the worst insect 
pest of tomatoes, and peas and beans are also subject to serious 
injury. Among tobacco-growers the insect is known as the 
bud-worm from its habit of boring into the roll of unopened 
leaves at the center of the plant. Other plants liable to more 
or less serious injury are okra, pepper, eggplant, pumpkin, 
squash, melon, cucumber, asparagus, peanut, coUards and 
potatoes. The insect also attacks sorghum, sugar-cane, millet, 
cowpeas, vetch, alfalfa and clover. Its wild food plants are 
numerous ; some of the more common are Jamestown weed, 
ground cherry, wild sunflower, cocklebur, bindweed, horse- 
nettle, velvet-leaf and hemp. Many ornamental plants are 
also attacked, such as gladiolus, geranium, mignonette, morning- 
glory and rose. When driven by hunger, the caterpillars will 
feed on almost any succulent vegetation they can find. Ripen- 
ing fruits, such as peaches, plums and even quinces, are some- 
times attacked. 

Throughout the greater part of the United States and Canada, 
the corn ear-worm hibernates in the pupal stage, but in southern 
Florida some of the moths remain active during the winter. 
The moths emerge in early spring over a period of at least a 
month. The moth has an expanse of about 1^ inches. In 
the commonest form, the front wing is straw-color, usually 
marked with a spot in the middle and frequently with a darker 
area near the tip. The spots may be entirely lacking or the 
wing may be heavily shaded with brown, and the wings are 
sometimes tinged with reddish or greenish. The hind wings 
are creamy white with a diffuse blackish border containing a 




CORN INSECTS 213 

pale spot and there is usually a dark spot near the middle of the 
wing. The flight of the moths is low, swift and irregular. They 
lay their eggs mostly on dark days or at dusk. The eggs are 
deposited singly on the leaves and stems of tomato, tobacco 
and cotton, and on the leaves, tassels and silk of corn, the last 
being preferred above all others for oviposition. Each female 
is capable of laying from 500 or ()()0 to over 2500 eggs. The egg 
(Fig. 134) is a little less than -^^ inch in diameter, waxy white, 
faintly tinged with yellowish, nearly globular, with the base 
flattened and the tip- depressed. The surface is marked with a 
series of ridges radiating from the tip. The first moths usually 
appear in the spring and are ready to lay their 
eggs before corn is a\'ailable. Under such cir- 
cumstances, eggs are deposited on early to- 
matoes, peas and beans. The time required 
for the hatching of the eggs varies with the 
temperature. In April they hatch in about a ^^^i V^'*- ~ ^^^ 

' , . , , of the corn ear- 

week, m the summer m two or three days worm(x30). 
and in the late fall in two weeks or over. The 
newly hatched larva is a little over -^ inch in length, nearly 
white, with the head and cervical shield black and the body 
marked with numerous small black tubercles. In the course 
of its development, the caterpillar usually passes through six 
stages but sometimes may pupate after the fifth stage. In the 
spring the caterpillars reach maturity in about a month ; in 
the summer, in from eleven days to three weeks, and in late 
fall, the larval period is again lengthened with the decreasing 
temperature. The corn ear-worm belongs to the same family 
as the cutworms and resembles them in general appearance. 
The full-grown caterpillar (Fig. 135) is 1-^ to 2 inches in length, 
varying from light green to brown. The coloration is highly 
variable but the caterpillar is usually marked with longitudinal 
stripes, the most distinct one being a pale stigmatal stripe 
edged above with blackish. There is a dark stripe along the 



214 MANUAL OF VEGETABLE-GARDEN INSECTS 



middle of the back divided by a narrow white line. The corn 
ear-worm might be mistaken for an army-worm of the summer 
brood, which it somewhat resembles, but may be distinguished 
by the granulose skin which under the microscope appears as 
if studded with minute hob-nails. 

When mature, the caterpillar leaves its food plant, descends 
to the ground and burrows into the soil in a slanting direction 
to a depth of two to seven inches, leaving the passage filled 
with loose earth. It then constructs a 
tunnel almost to the surface of the ground 
for the emergence of the moth. This 
tunnel is lined with compacted soil and a 
thin layer of silk. After completing the 
exit tunnel, the larva retreats to the en- 
larged lower part of the burrow and there 
transforms to a pupa. The pupa is 
smooth, brownish, f to nearly 1 inch in 
length and usually rests in a slanting posi- 
tion with the head upward. Pupae formed 
by the summer broods are usually found 
nearer the surface than those which winter 
over. The period passed in the pupal stage 
varies with the season. In the summer it is 
about two weeks and in the fall three weeks 
or more. The number of generations produced annually varies 
with the length of the season. Throughout the cotton belt there 
are probably four generations and sometimes a few moths of a 
fifth brood may emerge. In southern Texas and Florida seven 
generations may develop. In New Jersey and in other northern 
localities where the insect is a serious corn pest, only two 
or three generations occur. Farther north there is probably 
only one brood. After the first generation, the later ones 
become badly mixed, owing to the overlapping of broods caused 
by the irregular emergence of the moths, and the unequal 






Fig. 135. — The corn 
ear-worm, dorsal 
view (natural size). 



CORN INSECTS 215 

development of individuals. The later generations are only 
partial, owing to the fact that some of the pupae of these broods 
do not transform until the following spring. 

As a rule, tomatoes are most seriously injured by the corn 
ear-worm early in the season. At this time corn is not large 
enough to be attractive to the moths and they are forced to 
lay their eggs on tomato. The young larvse feed slightly on the 
leaves and may sometimes even burrow into the stem of the 
j)lant, killing it down to the point reached by the larva. The 
injury, however, is greatest to the fruit. The caterpillars bore 
into tomatoes of all sizes. A caterpillar does not, as a rule, 
remain long in one fruit but as soon as decay sets in leaves it, 
often entering several fruits in succession. It is not unusual 
in the South for half or more of the crop to be destroyed in 
this way. In New Jersey the injury is confined mostly to the 
early crop, but in Florida the attack may continue throughout 
the season. 

Peas and beans are often attacked by the corn ear-worm when 
corn is not available. The caterpillars bore into the pods and 
devour the seeds and may sometimes tunnel in the stems as well 
as feed to some extent on the foliage. Cucumber, squash, 
melons and pumpkin are sometimes injured, the larvae boring 
in the stems, and even entering the fruit. 

Corn may be attacked while still quite small. The eggs 
are deposited on the leaves and the caterpillars eat out irregular 
holes, especially in the tuft at the center of the plant. The 
moths begin depositing eggs in the silk as soon as it appears. 
On hatching, the young caterpillar usually devom"s its egg-shell 
and then works its way through the silk and in about twenty 
minutes reaches the tip of the ear, having fed very little if at 
all during this time. It then begins feeding on the silk and 
after a time burrows down under the husk, continuing to feed 
on silk and the unripe kernels (Fig. 136). The injury may 
extend halfway down the ear. The injured kernels and the 



216 MANUAL OF VEGETABLE-GARDEN INSECTS 



excrement left by the larva in its burrow under the husk serve 
as an excellent medium for the growth of various molds and 
bacteria, which greatly augment the injury inflicted by the 
insect. As many as six larvse sometimes infest an ear but 
usually only two or three are present, in spite of the fact that 
normally a much larger number of eggs are deposited on each 

mass of silk. This is to be 
accounted for by the can- 
nibalistic habits of the 
caterpillars. They feed 
voraciously not only on 
each other but on any other 
caterpillars that come in 
their way. 

Both field and sweet corn 
are subject to attack but 
the latter seems to be pre- 
ferred by the insect. The 
loss to field corn is not so 
great because the uninjured 
kernels can be used, but in 
the case of sweet corn good 
prices cannot be obtained 
for wormy ears. The pest 
is most destructive in the 
latter part of the season, 
owmg to the greater number of moths in the later broods. 
In the last crop of corn in the vicinity of New York, some- 
times nearly every ear is infested, while the earlier plantings 
may be practically free. In many parts of the South, it is 
mipossible to raise a clean crop of sweet corn because of 
the depredations of this insect. When full-grown, the cater- 
pillar leaves the ear, usually by gnawing a round hole through 
the husk, but in some cases it may escape at the tip. Some- 




FiG. 136. — Two full-grown ear-worms 
on the tip of an ear of field corn 
(natural size). 



CORN INSECTS 217 

times the larvte desert the ear when only partly grown and mi- 
grate to other ears on the same or nearby plants. In the cotton 
belt the later broods of caterpillars produced after corn has 
become hard are to be found mostly on cotton. In Iowa and 
Nebraska, late brood caterpillars have been found on alfalfa 
and clover. 

Control. 

No practical method of controlling the corn ear-worm on 
field corn has yet been disco\'ered. Experiments in New 
Jersey have shown that the injury to sweet corn may be greatly 
decreased by dusting the silk with a mixture of 50 per cent 
powdered arsenate of lead and 50 per cent finely ground sulfur. 
The first application should be made soon after the silk appears, 
followed by one or two others before the corn is ready to pick. 
Dust can be applied most conveniently by means of a small 
hand bellows carried under the arm and equipped with a piece 
of rubber hose abnut two feet long attached to the outlet by 
which the dust is directed downward into the tip of each ear. 

When sweet corn is grown for the cannery, early planting 
is advisable, but cannot be practiced when corn is grown 
for the market because for this purpose a succession cover- 
ing as long a period as possible is required. IMuch benefit 
may be derived from fall or winter plowing land on which an 
infested crop has been grown in order to destroy the pupje. As 
large an area as possible should be included in this treatment 
as the moths are capable of flying a considerable distance. 

The injury to tomatoes may be in part prevented by spraying 
the vines with arsenate of lead f paste), 4 to G pounds in 100 
gallons of water, making one or two applications before the 
fruit is half grown. Later applications are likely to stain the 
fruit. Injured tomatoes should not be left in the field but 
should be picked along with the others, sorted in the packing- 
house and should then either be buried or dumped into a pond. 



218 MANUAL OF VEGETABLE-GARDEN INSECTS 

Tomatoes can also be partially protected from the corn ear- 
worm by using corn as a trap crop on which, in preference to 
the tomatoes, the moths will lay their eggs. Two rows of corn 
should be planted for every ten or twenty rows of tomatoes 
and so timed as to come into silk when the first tomatoes are 
forming. It should be cut and destroyed before the cater- 
pillars reach maturity. 

References 

Comstock, Rept. Cotton Insects, pp. 287-315. 1879. 

Riley, 4th Rept. U. S. Ent. Comm., pp. 355-384. 1885. 

Mally, Rept. on Bollworm, Tex. Agr. Col. 1902. 

U. S. Farm. Bull. 191. 1904. 

U. S. Bur. Ent. Bull. 50. 1905. Bibliography. 

U. S. Farm. Bull. 290. 1907. 

Ky. Agr. Exp. Sta. Bull. 187. 1914. 



The Corn Root-Aphis 

Aphis maidi-rndicis Forbes 

Although the corn root-aphis is generally distributed through- 
out the United States east of the 100th meridian, it is most 
injurious in the corn belt and in New Jersey, Delaware and 
eastern Pennsylvania. In the South Atlantic states, it has 
proved a troublesome pest of cotton and has also been known 
to infest the roots of cultivated asters in Illinois. There is 
some doubt as to many of the wild food plants of the corn 
root-aphis because of confusion with a similar species, Aphis 
middletoni Thomas, often found on the roots of certain wild 
plants such as asters and Erigeron. It is, however, ^definitely 
recorded from smartweed, knot weed, crab-grass, purslane, dock, 
fo.xtail, fleabane, mustard, sorrel, plantain, pigweed, great 
ragweed, thorny amaranth, green amaranth, Roman wormwood, 
dog fennel, shepherd's purse, lamb's quarters, poverty weed, 
buttonweed, purplish cudweed, sneezeweed, pineweed, dwarf 



CORN INSECTS 219 

dandelion, pepper-grass, toadflax, mild water pepper, cockle- 
bur, vervain, common nightshade, skullcap, Teucrium laciniatum, 
Leptochloa filiformis and Mentha arvensu. 

The corn root-aphis has been studied most carefully in 
Illinois. The insect passes the winter in the egg stage in the 
care of a little brown ant, Lasius niger americanus Emery. 
The ants tend the aphids in much the same way as man cares 
for domestic animals, being very fond of the sweetish liquid, 
known as honeydew, secreted by them. This aphis has become 
so dependent on the ants for the care of the winter eggs and for 
placing the young lice on the roots of their food plants that they 
would doubtless all perish were there no ants present to attend 
them. The eggs are stored in the ants' nest, where. they are 
protected by the workers as carefully as are the young of their 
own species. Sometimes in warm days in early spring, the 
ants carry the eggs to the upper galleries of the nest or even 
lay them out in the sunshine and carry them back at night. 
This is probably done in order to keep the eggs in good condition 
and to hasten their hatching. In central Illinois the eggs begin 
to hatch in early April, just as the smartweed, pigeon-grass and 
ragweed plants are coming up. The young aphids are carried 
by the ants and placed on the roots of these weeds. Here they 
are attended by the ants, whose burrows are extended to include 
the roots. The young aphids pass through four nymphal stages 
in the course of their growth and reach maturity in about 
nineteen days, on the average, in Illinois. As the eggs hatch 
over a considerable period, usually from early April to the last 
of May, the last nymphs hatched will find themselves surrounded 
by representatives of three generations. All the individuals 
of the first generation are wingless but in the later generations 
there is a varying percentage of winged forms produced. The 
latter occur in greatest numbers when the roots are crowded 
and food is scarce. The winged forms leave the roots, come 
to the surface and take flight, seeking new feeding grounds. 



220 MANUAL OF VEGETABLE-GARDEN INSECTS 




Fig. 137. — Wingless vi 
viparous female corn 
root aphis (X 13). 



During the summer only two forms of the aphids occur, wing- 
less and winged viviparous females ; males and egg-laying 
females are not produced till October or 
November and constitute the last genera- 
tion of the season. From eleven to 
twenty-two generations are produced 
annually, each female giving birth to 
nearly fifty young. With the advent of 
cool weather, wingless egg-laying females 
and wingless, or rarely winged, males 
are produced. The small black eggs are 
deposited underground in the galleries of 
the ants where they are cared for till 
the following spring. The full-grown 
viviparous female (Fig. 137) is about ys 
inch in length, bluish green, dusted with a whitish waxy 
pulverulence. The head and transverse bands on the thorax 
are black. In the winged form, the head and thorax are 
black or dark brown and the abdomen is pale green with 
three distinct black 
spots on each side 
(Fig. 138). _ 

By the time the 
corn is planted and 
comes up, the 
aphids have become 
crowded on the 
roots of the weeds 
and many winged 
forms have devel- 
oped. At this time 
the weed roots have 
become hardened and are thus less favorable for the develop- 
ment of the lice. The ants transfer many of the wingless 




Fig. 138. 



Winged viviparous female corn-root 
aphis (X 16). 



CORN INSECTS 221 

aphids from the weeds to the corn roots and also seize any of 
the winged migrating forms that come their way and carry 
them down to the roots. In this way the corn soon becomes 
badly infested. The injury is ordinarily first noticed in irregular 
patches usually on the lower ground. The loss of sap caused 
by the feeding of the aphids lessens the vitality of the plant, 
causing the leaves to turn yellowish or reddish. The aphis is 
most destructive in years of drought because under such condi- 
tions the plants are least able to bear the loss of sap. Corn 
plants badly stinited by the root-aphis often fail to bear ears 
or produce only nubbins. 

Control. 

Experiments and the experience of practical corn-growers in 
Illinois have shown that the losses caused by the corn root- 
aphis may be in large measure prevented by plowing land 
intended for corn to a depth of six or seven inches early in the 
spring followed by thorough and repeated disking to break up 
the ants' nests and scatter the eggs of the aphis. This treat- 
ment also destroys the weeds on which the root-lice get their 
start. It also puts the soil in good tilth, making possible a 
strong and rapid growth of the corn. Corn is most likely to 
be injured by the root-aphis when the crop is grown on the same 
land for two successive years. INIuch injury may, therefore, 
be avoided by adopting a rotation in which corn does not 
follow corn. As a supplementary treatment, S. A. Forbes 
recommends the use of oil of tansy applied to each hill as a 
deterrent for the ants. One fourth pound of oil of tansy 
and 1 gallon of wood or denatured alcohol is mixed with 
100 pounds of bone-meal. This is enough for an acre and 
should be applied with a fertilizer dropper attached to the 
planter. Careful preparation of the soil and thorough culti- 
vation will tend to make the plants able to outgrow injury by 
root-lice. 



222 MANUAL OF VEGETABLE-GARDEN INSECTS 



References 

Forbes, 14th Kept. State Ent. 111., pp. 23-33. 1885. 

Forbes, ISth Rept. State Ent. 111., pp. 58-85. 1894. 

111. Agr. Exp. Sta. Bull. 44, pp. 237-256. 1896. 

111. Agr. Exp. Sta. Bull. 104, pp. 102-123. 1905, 

111. Agr. Exp. Sta. Bull. 130. 1908. 

111. Agr. Exp. Sta. Bull. 131. 1908. 

U. S. Bur. Ent.' Tech. Bull. 12, pp. 123-144. 1909. Bibliogravhy. 

U. S. Bur. Ent. Bull. 85, pp. 97-118. 1910. 

111. Agr. Exp. Sta. Circ. Jan. 9, 1913. 



The Southern Corn Root-Worm 

Diabrotica duodecimpunctata Fabricius 

The southern corn root-worm is also known as the twelve- 
spotted cucumber beetle and in the South as the corn bud-worm 

from the habit of the larvae of kill- 
ing the bud or central leaves of 
the young corn plant. The beetle 
is generally distributed through- 
out the United States and southern 
Canada east of the Rocky Moun- 
tains southward to Florida and 
Mexico. It is injurious to corn 
from southern Illinois to Virginia 
and southward. 

The beetle (Fig. 139) is about 
^ inch in length, with the head 
black and the thorax and wing- 
covers yellowish green. Each 
wing-cover is marked with six 
black spots arranged in three transverse rows. The antennae 
and legs are black ; the first three joints of the antennse and 
basal half of the femora are pale. The beetles hibernate 
under any convenient shelter, often in alfalfa fields. In the 




Fig. 139. — The southern corn 
root- worm beetle ( X 5) . 



CORN INSECTS 223 

South they are dormant only for a few days at a time during 
periods of cold weather, and in southern Florida and Texas 
the beetles are active throughout the winter. The adults feed 
on a great variety of plants both wild and cultivated. They 
are often found in the blossoms of squash, pumpkin, melon 
and cucumber, feeding on the pollen. They also attack 
seedling cucurbits in much the same way as .the striped 
cucumber beetle and often gnaw holes in the fruit. They 
sometimes seriously injure young beans, peas, cabbage, cauli- 
flower, kale, turnip, mustard, rhubarb, asparagus, eggplant, 
potato, tomato and beet and there is a record of their being 
destructive to spinach in New Mexico. The beetles are often 
found in the spring feeding on the blossoms of fruit-trees and 
later in the season on the flowers of cotton and on the silk 
of corn, but they are probably most abundant on the flowers 
of various wild plants such as goldenrod, wild sunflower and 
many others. The larvje are found most abundant on the 
roots of corn but they also attack the roots of bean, rye, wheat, 
millet, alfalfa, southern chess, barnyard-grass, Johnson-grass, 
golden glow, Jamestown weed and pigweed (Amaranthus). 

The beetle deposits her eggs in early spring in cracks and 
crevices of the ground around the base of the plant. A single 
female has been known to lay over 500 eggs, but the average is 
probably much less. Only a few days are required for the beetle 
to lay her full complement of eggs, but as all the beetles do not 
mature at the same time, egg-laying will continue over a period of 
a month or more. The egg is dull yellow, oval and about tV 
inch in length. The eggs hatch in a week to over three weeks 
and the young larva begins feeding on the roots. In the case 
of young corn plants, the grubs often enter the stalk near 
the upper circle of roots, killing the bud or inner leaves, or they 
may eat out irregular holes in the root, often severing them 
from the plant. The injury is usually most severe to corn 
growing in low wet land. The larva becomes mature in fifteen 



224 MANUAL OF VEGETABLE-GARDEN INSECTS 

to thirty-five days. It is then a slender grub, about i inch in 
length, whitish or yellowish in color with the head and cervical 
shield brownish. When full-grown, the lar\'a leaves the plant 
and constructs a small earthen cell within which it transforms 
to a small whitish pupa, the beetles emerging in one to two 
weeks. Throughout the greater part of the insect's range, 
there are two generations annually. In the extreme South 
where the beetles are active during the entire year, an additional 
generation may develop. The larvae of the second generation 
are not so injurious to corn as those of the first but they some- 
times injure the roots so that the plants are easily blown 
over by storms and in some cases ripening is delayed and the 
size and quality of the crop reduced. 

In the southwest, a variety of the southern corn root -worm 
has received the name of tenella Leconte. In this form the 
spots on the wing-covers are greatly reduced in size and the 
posterior ones may be entirely lacking. 

Control. 

Injury to corn by this insect may be in large measure pre- 
vented by planting late, after the beetles have deposited most 
of their eggs. Corn planted the first of May in Alabama will 
usually escape injury. Farther north the corresponding date 
would be somcAvhat later. In the case of sweet corn when 
it is desirable to plant the crop early, it is often possible to get 
a good stand in spite of the root-worms by planting an excess 
of seed. A rotation of crops has not proved of much value in 
preventing injury because the beetles are good fliers and readily 
find their way to corn fields for egg-laying. Since the injury 
to corn is usually most severe on low wet land, tile drainage is 
often the most practical method of solving the problem. 

When attacking cucumbers, squashes and melons, the beetles 
may be controlled by the measures suggested for the striped 
cucumber beetle on page 111. 



CORN INSECTS 225 



References 



Garman, Psyche, 6, pp. 28-30; 44-49. 1891. 

Ky. Agr. Exp. Sta. Kept, for 1890, pp. 9-22. 1894. 

Quaintance, U. S. Div. Ent. Bull. 26, pp. 35-41. 1900. 

U. S. Bur. Ent. Circ. 59. 1905. 

Ala. Agr. Exp. Sta. Circ. 8. 1911. 

S. C. Agr. Exp. Sta. Bull. 161. 1912. 

U. S. Dept. Agr. Bull. 5. 1913. 



The Western Corn Root-Worm 

Diabrotica longicornis Say 

The western corn root-worm is also known as the northern 
corn root-worm, neither name being especially appropriate ; 
the former because there is no eastern corn root-worm and the 
latter because the species also occurs in the South. Although 
the insect ranges from Nova Scotia to Dakota and southward 
to Alabama and Mexico, it has been noticeably destructive to 
corn only in the specialized corn-growing region from Ohio to 
Nebraska and Kansas. The winter is passed in the egg stage 
in the ground, usually in fields in which corn grew the preceding 
year. The egg is about ^V inch in length, oval and dirty white 
in color. The eggs are deposited by the beetles in late summer 
or fall in the ground within a few inches of the corn plant. The 
female burrows into the soil for oviposition and deposits her 
eggs in loose groups from three or four to eight or ten. The eggs 
hatch in the spring over a considerable period and the larvae 
soon find their way to the roots of the young corn plants in case 
the field is again planted to this crop. They feed on the 
smaller roots and tunnel out the larger ones, making a slightly 
sinuate burrow on the side of the root just below the surface. 
Many of the roots are killed in this way and by the decay that 
often accompanies the injury. After destroying one rot)t, the 
grub often attacks a second but as a rule does not burrow into 

Q 



226 MANUAL OF VEGETABLE-GARDEN INSECTS 



the crown. As far as known, corn is the only food plant of the 
larvae, but it is probable that they also feed on the roots of 
broom corn and sorghum. The injury to the roots inflicted by 
the grubs, if severe, may cause the plants to remain dwarfed 
and sickly or may merely weaken them so that few or imperfect 
ears are produced. When many of the roots have been 
destroyed, the corn is likely to be blown over by the wind. The 
larvae mature from late June to late August. They are then 
elongate, slender, whitish grubs with the head, cervical shield 

and anal plate yellow- 
ish brown and are 
about f inch in length. 
When full-grown, the 
larva leaves the root 
and transforms within 
a small earthen cell to 
a whitish pupa. The 
beetles of the new 
brood emerge over a 
long period, from 
about the first of July 
until September. 
They are about ^ inch 
in length and grass-green in color with the antennae brownish, 
paler towards the base (Fig. 140) . In Illinois the eggs are mostly 
laid between the first of August and the early part of October. 
There is only one generation annually. The beetles feed on 
the pollen and silk of corn and are often found on the blossoms 
of buckwheat, goldenrod, smartweed, thistle and many other 
wild plants as well as in the flowers of cucurbits. They some- 
times gnaw into the unripe kernels of corn where the husk has 
been broken and have been known to gnaw holes in the rind of 
pumpkin and squash and to feed on the leaves of radish and 
turnip. 




Fig. 140. — The western corn root-worm 
beetle (X 8). 



CORN INSECTS 227 

Control. 

Owing to the eggs of the western corn root-worm being 
deposited only in corn fields, injury may be avoided by not 
planting land to corn for more than two years in succession. 

References 

Forbes, 12th Kept. TU. State Ent. for 1882, pp. 10-31. 
U. S. Dept. Agr. Bull. 8. 1913. 

The Colorado Corn Root-Worm 

Dinhroticn virgifera Leconte 

In Colorado, sweet corn is sometimes seriously injured by 
a larva similar to that of the southern corn root-worm that 
burrows into the stalk below ground. The female beetle is ^ 
inch in length and closely resembles the striped cucumber beetle 
in general appearance, but in the male the wing-cover is black 
except for a narrow yellow margin and a yellow spot near the 
tip. The beetles are often troublesome in vegetable-gardens 
where they feed on a variety of plants. The eggs are pale 
yellow and about ^V i"<^'h in length. They are laid in the fall 
in the ground near the corn plants and do not hatch till the 
following spring. The larva is a little less than | inch in length, 
pale yellow, with the head and anal plate black. The insect 
is apparently single brooded in Colorado. 

Injury by this species may be prevented in large measure by 
not growing corn for successive years on the same land. 

Reference 
Gillette, Jour. Econ. Ent., 5, pp. 364-366. 1912. 



228 MANUAL OF VEGETABLE-GARDEN INSECTS 

The Larger Corn Stalk-Borer 

Diatrcea zeacolella Dyar 

In the southern states northward to Kansas and Maryland, 
corn is sometimes attacked by a whitish caterpillar marked with 
dark brown spots. This insect is closely related to the sugar- 
cane borer and until recently the two have been considered the 
same. These caterpillars bore into the stalks of young corn, 
causing the plants to become dwarfed and distorted. They 
often bore through the unopened leaves, producing groups 
of small holes symmetrically arranged on the two halves of the 
expanded leaf. The larvse of the second generation burrow into 
the stalks below the second or third joint, weakening them so 
that the plants are easily blown over by the wind. The insect 
hibernates as a full-grown larva in a burrow in the tap-root 
below the surface of the ground. Pupation takes place in the 
spring within the burrow and the moths emerge in ten days or 
more. The straw-yellow moth, with an expanse of 1 to 1| 
inches, lays her eggs in clusters of two to twenty-five, either on 
the lower or more rarely on the upper side of the leaves of the 
young corn. The egg when first laid is creamy white, gradually 
changing to orange-brown, flattened, oval, slightly convex 
and about -^ inch in length. In the cluster the eggs overlap 
and are usually arranged in two, three or four rows. The egg 
hatches in a week to ten days and the young caterpillars at first 
feed on the upper leafy part of the young plant but soon bore 
down into the stalk. There is considerable migration of the 
caterpillars from plant to plant and a borer may leave the 
stalk at one place only to re-enter at another point. The 
caterpillars mature in twenty to thirty days. The full-grown 
larva is about an inch in length, dirty white, usually marked 
with numerous dark brown spots. When about to pupate, the 
caterpillar cuts through the stalk an exit hole for the moth 



CORN INSECTS 229 

which is covered with silk and the burrow is plugged below with 
a mass of frass. The shining brown pupa is nearly an inch in 
length. The mt)ths of the second brood emerge in six to ten 
days and lay eggs for another brood of larvae. These borers 
riddle the stalks near the base with numerous burrows and 
when mature descend to near the surface of the ground, where 
they usually remain in the larval condition till the following 
spring. These hibernating larvai are nearly pure white, the 
brown spots having disappeared. There are apparently only 
two generations annually. 

Control. 

Tlie most practical measure so far suggested for the control 
of this insect is the adoption of a proper system of crop rotation. 
In this system corn should not follow corn. When it is necessary 
to plant corn after corn, the stalks and stubble should be raked 
up and burned before the moths emerge in the spring. 

References 

Comstoek, U. S. Ent. Rept. for 1880, pp. 243-245. 1881. 

Howard, Insect Life, IV, pp. 95-103. 1891. 

U. S. Farm. Bull. 634. 1914. 

Holloway, Jour. Agr. Research, VI, pp. 621-625. 1916. 

The Lesser Corn Stalk-Borer 

Elasmopalpus lignosellus Zeller 

In the southern states, corn, sugar-cane, cowpea, bean and 
peanut are sometimes attacked by a small greenish, brown- 
striped caterpillar that burrows in the stalk at or just below the 
surface of the ground. It is most injurious on thin sandy or 
gravelly land. The insect has also been recorded as infesting 
crab-grass and Johnson-grass. It ranges from Maine along the 
coast to Pennsylvania westward to Iowa, Texas and southern 
California and southward to Patagonia. 



230 MANUAL OF VEGETABLE-GARDEN INSECTS 

Hibernation takes place in three stages : larva, pupa and 
adult. In South Carolina the insect usually enters the winter 
in the larval state but may transform to a pupa before spring. 
The egg is greenish white to reddish, ovate, about 3V inch in 
length. The time and method of depositing the eggs in the 
field have not been recorded. The eggs hatch in about three 
days in the summer and in five days to a week in the fall. 
The caterpillars burrow into the young corn plant near the 
surface of the ground and kill the central tuft of leaves, often 
causing the plant to die or leaving it in a dwarfed, deformed 
condition, incapable of bearing a crop. The larva becomes 
mature in two or three weeks, depending on the season. In the 
late fall it may require nearly six weeks to reach maturity. In 
the course of its growth, the larva molts from four to six times. 
When full-grown, it is about f inch in length, greenish in color, 
whitish above and the body is marked with nine narrow longi- 
tudinal brownish stripes and crossed by a broad brown band 
on the posterior margin of each segment. The head and cervical 
shield are shining dark brown, with a pale line running over the 
top of the head and crossing the shield. The larvte do not 
remain in their burrows in the plant except when feeding but are 
usually found in a thin silken tube, in which bits of excrement 
and grains of sand are incorporated, attached to the side of the 
plant just below the surface of the ground. In feeding on the 
older corn plants, they not only burrow into the stalk but also 
girdle the plant, causing it to break over easily. Several larvaj 
may infest a single plant. When mature they construct oval 
silken cocoons covered with particles of sand and dirt in which 
they transform to brownish pupae about ^ inch in length. The 
moths emerge in one to three weeks, depending on the tempera- 
ture. The moth has an expanse of f to 1 inch. In the male 
the front wings are light brownish yellow, usually dark gray 
on the margins with two or three small dark spots on the disk. 
The hind wings are whitish, edged with light brown. In the 



CORN INSECTS 231 

female the front wings are darker, sometimes nearly black but 
forms occur in which they are reddish. The moths are inacti\'e, 
feign death when disturbed, and fall to the ground with wings 
and antennjTe drawn closely to the body. Their flight is swift 
but of short duration. There are apparently four generations 
annually in South Carolina. 

The injury caused by the lesser corn stalk-borer may be 
prevented in part by clearing the field of crop remnants in 
the fall and by plowing the land in late fall or early winter 
to destroy the insects in their winter quarters. In some cases 
early planting will cause the crop to escape serious infestation. 

References 

Riley. TJ. S. Ent. Rept. for ISSl and 1S,S2, pp. 142-145. 
U. S. Div. Ent. Bull. 23. pp. 17-22. 1900. 
U. S. Dept. Agr. Bull. 539. 1917. 

The Brown Fruit-Chafer 

. Enphorin inda Linnaeus 

The ears of sweet corn are sometimes injured in the fall 
by a thick-set, yellowish brown beetle \ inch or more in length. 
Its wing-covers are sprinkled all over with small, irregular black 
dots. These beetles appear in late summer or early fall and feed 
on the pollen of flowers, ripe fruit and corn in the milk. They 
attack the tip of the ear, working down under the husk and 
devouring the unripe kernels. After feeding for some time, they 
go into hibernation and very early the next spring may be seen 
flying close to the ground with a loud buzzing sound. 

The female deposits her white, nearly spherical eggs in the 
vicinity of manure heaps, in piles of rotting sod and other 
decaying vegetable matter. When full-grown the larva is some- 
what over an inch in length, strongly curved and dirty white 
in color ; the posterior part of the body has a dull leaden hue 



232 MANUAL OF VEGETABLE-GARDEN INSECTS 



from the contents of the alimentary canal. It differs from the 
white grub (Lachnosterna) in its shorter and more robust form, 
in the shorter legs and smaller head, and in its habit of crawling 
on its back. In July the larvre pupate within earthen cocoons 
of a somewhat angular external form. The beetles emerge 
during August and September. There is only one generation 
a year. 

Hand-picking of the beetles is apparently the most practicable 
means of controlling this insect when it is found working on 
sweet corn. 

Stink-Bugs 

Two species of stink-bugs, Euschistus mriolarms Palisot de 
Beauvais and E. euschistoides Snellen van Vollenhoven, some- 
times injure sweet corn by puncturing the 
kernels through the husk. They suck out 
the juice, causing the kernels to become 
sunken or to pop open. The 
kernels become infected with mold 
These stink-bugs are about ^ 
length, dull grayish 
brown, sometimes tinged 
with reddish or greenish 
and dotted with numer- 
ous black punctures. In 
E. Dariolarius (Fig. 141) 
the sides of the pro- 
thorax are acutely pointed, while in E. 
euschistoides (Fig. 142) they are rounded. 
In the male of the former, there is a dis- 
tinct black spot on the underside of the last 
abdominal segment. 

The first mentioned of these bugs has also been recorded as 
injuring tobacco, raspberries, peaches and strawberries. It has 




injured 



inch in 



Fig. 141. — Euschis- 
tus variolar ius, adult 
(X2). 




Fig. 142. — Euschistus 
euschistoides, adult 
(X2). 



CORN INSECTS 233 

been known to puncture ripening tomatoes and the stems of 
melon, asparagus and the pods of okra. The adults are to 
be found throughout the summer and the insect is said to hiber- 
nate in this stage. The life history of each species has not been 
fully recorded. 

These stink-bugs are most abundant on corn and tomatoes 
raised in the vicinity of waste land grown up to rank weeds. 

Other Corn Insects 

Cabbage wobworni : 1(5 

Seed-corn inajj:got : 3(j 

Green soldier-bug : 42 

False chinch-bug : 47 

Yellow bear caterpillar : 3.57 

Carrot beetle : 185 

Negro-bug : 196 

Western twelve-spotted cucumber beetle: 114 

Belted cucumber beetle : 115 

Common stalk-borer : 157 

Burdock borer : 160 

Bean leaf-beetle : 65 

Garden flea-hopper : 77 

Spotted cutworm : 262 

Well-marked cutworm : 263 

Greasy cutworm : 265 

Dark-sided cutworm : 268 

Striped cutworm : 270 

Dingy cutworm : 271 

Granulated cutworm : 273 

Clay-backed cutworm : 274 

Variegated cutworm : 276 

Glassy cutworm : 279 

Yellow-headed cutworm : 281 

Spotted-legged cutworm : 282 

Bristly cutworm : 285 

Bronzed cutworm : 286 

Army cutworm : 287 

Fall army-worm : 292 

Beet army-worm : 294 

Yellow-striped army-worm : 295 

Black blister-beetle : 307 



234 MANUAL OF VEGETABLE-GARDEN INSECTS 

Potato flea-beetle : 314 
Pale-striped flea-beetle : 321 
Smartweed flea-beetle : 323 
Western cabbage flea-beetle : 327 
Desert corn flea-beetle : 334 
Millipedes: 342 
Slugs: 354 

Wheat wireworm : 348 
Sugar-beet wireworm : 349 
Corn and cotton wireworm : 349 



CHAPTER XII 

SWEET POTATO INSECTS 

The sweet potato in the United States is not, as a rule, 
subject to serious injury by insects, except in limited areas 
where the weevil has become established. When the plants 
are just set out, they are likely to be attacked by flea-beetles 
(see page 332) and by tortoise beetles. In Florida the late 
crop is often seriously injured by the sweet potato white-fly. 

The Tortoise Beetles 

Sweet potato vines are subject to injury soon after trans- 
planting by several species of tortoise beetles that eat out 
more or less circular holes in the leaves. These leaf-beetles 
are flattened below and convex above and have the margins 
of the prothorax and wing-covers broadly expanded and more 
or less semi-transparent, giving the insect a regularly oval 
outline. The head is concealed under the expanded margin 
of the prothorax. The beetles have a striking resemblance 
in form to miniature turtles — hence their common name. The 
larvae are sometimes known as peddlers from their habit of 
carrying their cast skins and excrement in a pack over the 
back supported on two long spines arising at the posterior 
end of the body. Along the edge of the body is a row of rather 
large branched spines. 

In New Jersey, the beetles appear on the sweet potato plants 
as soon as they are transplanted in late May or early June 
and, after feeding for a time, lay eggs from which a new brood 

235 



236 MANUAL OF VEGETABLE-GARDEN INSECTS 

of beetles is produced in July. The new beetles feed for a 
short time and then go into hibernation. There is only one 
generation a year, at least in the northern states. 

The striped tortoise beetle, Cassida bivittata Say 

This is the commonest and most injurious species attacking 
sweet potatoes in New Jersey and is widely distributed through- 
out the regions in which this crop is grown in the eastern United 
States. The beetle (Fig. 143) is about -^ inch in length ; the 
prothorax is reddish with the margin yellowish ; 
the wing-covers are dull yellow marked with five 
longitudinal black stripes ; the underside of the 
body and the legs are dark brown or black. The 
beetles appear in the field in early spring and 
feed for a time on wild morning-glory and attack 
the sweet potato plants as soon as they are set 
Fig 143 — The ^^^ ^" ^^^ field. The eggs are glued to the under- 
striped tor- side of the leaves singly and hatch in a few days. 
( x^5) ^^^^^^ The larva is yellowish white with a grayish longi- 
tudinal line along the middle of the back. This 
larva differs from the other species infesting the sweet potato in 
not mixing excrement with the cast skins carried on the anal fork. 
This appendage is not carried close to the back but is usually 
elevated at an angle of about 45 degrees. When full-grown, 
the larva attaches itself to the leaf by the tip of its body and, 
after resting for two days, the larval skin splits along the back 
and is pushed back towards the hind end of the body where it 
is retained surrounding the point of attachment. When fully 
colored, the pupa is dull brownish and may be distinguished 
from the other species by the elongate whitish mass of cast 
skins on the anal fork which still adheres to the insect. The 
beetles emerge in July and after feeding a short time on the 
leaves of sweet potato and wild morning-glory go into hiber- 
nation early. 




SWEET POTATO INSECTS 



237 




The black-kgged tortoise beetle, Cassida nigripes 01i\'ier 

This beetle (Fig. 144) is a little over i inch in length. When 
at rest in the sunshine, it is of a beautiful golden tint but loses 
its brilliancy when disturbed and after death fades to a yel- 
lowish brown. Each wing-cover is marked with three black 
spots arranged in a triangle. The legs and 
the tip of the antennse are black. The eggs 
are laid in rows of three to twelve on the 
stems of the plant. The laryse are bright 
straw-yellow with a curved black mark on 
each side of the prothorax. The spines along 
the side of the body are tipped with black. 
The anal fork is carried close to the back and 
the excrement is arranged in a characteristic yig. 144. — Thehiack- 
manner with long shreds extending out side- lagged tortoise beetle 
wise. The pupa is dark brown with the 
lateral spines transparent white. The larvse reach maturity in 
about two weeks and the pupal period is nearly as long. 

TIic golden tortoise beetle, Coptocycla bicolor Fabricius 

When basking in the sunshine, this beetle has been likened 
to a drop of molten gold ; the coloration becomes duller, how- 
ever, when the insect is disturbed or in 
cloudy weather and after death fades to a 
light reddish brown. The scientific name, 
bicolor, was apparently given because of 
the contrast between the golden central 
part of the body and the thin semi-trans- 
parent margin. The beetle (Fig. 145) is 
a little over ^ inch in length. The 
eggs are glued singly to the underside of 
the leaf. The egg is about ^ inch in length, dirty white in 
color, rounded below, ridged on the sides above and is usually 
armed at one end with three sharp diverging spines. The 




Fig. 145. — The 
golden tortoise 
beetle (X o). 



238 MANUAL OF VEGETABLE-GARDEN INSECTS 

larva is dark brown in color, lighter on the back and is com- 
pletely covered by the large mass of excrement carried on the 
anal fork. The larva becomes mature in about eighteen days 
and transforms to a brown pupa with three dark stripes on the 
transparent prothorax. The covering of excrement is retained 
during the pupal period, which lasts a week to eleven days. 
In addition to sweet potato and wild morning-glory, this in- 
sect occasionally feeds on bittersweet. 

The mottled tortoise beetle, Coptocycla signifera Herbst 

This beetle (Fig. 146), which is about ^ inch in length, is readily 
distinguished from the others feeding on sweet potato by having 
the disk and the front margin of the wing- 
covers black, mottled with gold or yellow. 
The disk of the prothorax is black and 
contains two yellow spots. The larva is 
green in color, bluish along the back. The 
excrement is arranged on the anal fork 
„ ,.„ „, ^ in broad masses, sometimes with shreds 

Fig. 146. — The mot- . ' 

tied tortoise beetle extending from the sides. The larva be- 
^'^'*^' comes mature in about sixteen days and 

transforms on the leaf to a green pupa marked with a con- 
spicuous black ring around the first abdominal spiracle. This 
species is not confined to sweet potato and wild morning-glory 
but also attacks buckeye and thorn. 

The argus tortoise beetle, Chelymorpha argus Herbst 

This species has been reported as occasionally attacking the 
sweet potato. It is ^^ to t^ inch in length and varies in color 
from brick-red to clay-yellow. The wing-covers are marked 
with thirteen black spots and the prothorax usually with 
six, arranged in two rows. It has also been reported as 
feeding on milkweed, sunflower, wild morning-glory and 
horse-radish. 




SWEET POTATO INSECTS 



239 



Control. 

Tortoise beetles are readily killed by spraying the vines 
with arsenate of lead (paste), 2 pounds in 50 gallons of water, 
taking care to spray the mixture on the underside of the leaves. 
The young plants may also be protected from injury by dipping 
them in a mixture of arsenate of lead and water as recommended 
for the control of the sweet potato flea-beetle on page 333. 

Reference 
Walsh and Riley, Am. Ent., 1, pp. 234-238. 18G9. 



The Sweet Potato Weevil 

Cylas formicarius Fabrieius 

This highly destructive pest of the sweet potato is a native 
of the tropics. It was first seen in the southern United States 
in 1875 and now occurs from Georgia and 
Florida westward along the Gulf of Mexico 
into Texas. The insect is also found in India, 
Australia, Cochin China, Java, Madagascar 
and the West Indies. The adult is a slender 
snout-beetle about ^ inch in length (Fig. 147). 
The head is dusky black ; the prothorax and 
legs are reddish and the wing-covers a metallic 
bluish black. The prothorax is strongly con- 
stricted near the hind margin ; the snout is 
stout and is carried projecting forward. The 
beetles are decidedly ant-like both in form and 
coloration. While they possess functional wings, they rarely 
use them, but are sometimes attracted to lights. 

The beetle deposits her creamy white, elongate oval eggs, 
about 3^ inch in length, singly in a small hollow eaten out 
in the stem or in a tuber that has become exposed. The eggs 
hatch in four to six days. The larvie hatching in the stems 




Fig. 147. — The 
sweet potato 
weevil (X 4|). 



240 MANUAL OF VEGETABLE-GARDEN INSECTS 

burrow downward through the center to the tuber. On reach- 
ing the potato, its burrow becomes somewhat hirger and winds 
aimlessly through the flesh. The full-grown larva is about 
Ys inch in length, the body is white and the head yellowish 
or brownish. The grubs become mature in two to three weeks. 
The tissue surrounding the burrow becomes discolored and decay 
sets in, giving the tuber a peculiar odor. When mature the 
grub eats out an oval cavity and after resting a day or two 
transforms into a white pupa about ^ to ^ inch in length. The 
pupal period occupies five to eight days, and after waiting 
two or three days to harden, the beetle eats its way out of the 
pupal cell. The beetles may then either leave the potato or 
may deposit eggs for another brood in the same tuber. Several 
hundred larvje may occupy the same potato and breeding may 
continue until all food material has been destroyed. Gen- 
eration after generation follow each other as long as food is 
available, but the beetles are able to exist for a long period 
without eating and resume reproductive activity when food is 
again available. The life cycle is completed, under favorable 
conditions, in about a month. The beetles are rather general 
feeders and are often found feeding on species of wild morning- 
glory and it is believed they can breed in these plants. 

The sweet potato weevil is a most destructive pest and has 
caused the abandonment of the growing of sweet potatoes in 
many localities. It is especially injurious to the potatoes in 
storage pits, where breeding may continue until the tubers are 
entirely consumed. 

Control. 

Under conditions obtaining in the southern states, the in- 
juries inflicted by this weevil may be prevented in large measure 
by not planting sweet potatoes on or near infested fields. In 
some localities it would pay to abandon the crop over a large 
area for two or three years in order to starve out the weevils. 



I 



SWEET POTATO INSECTS 241 

Infested tubers sliould not be left in the field. Those only 
slightly injured may be fed to stoek but those more badly in- 
fested should be burned or buried deeply. Care should be 
taken not to introduce the wee\'il into uninfested localities by 
means of infested tubers used for seed. 

References 

Tryon, Queensland Agr. Jour., 7, pp. 17G-189. 1900. 
Tex. Agr. Exp. Sta. Bull. 93. 

Maxwell-Lefroy, Mem. Dept. Agr. India, Ent. Series, 2, pp. 155-159. 
1910. 

The Sweet Potato Leaf-Roller 

Pilocrocis tripunctata Fabrieius 

A leaf-roller has been reported as occasionally injurious to 
sweet potatoes in southern Texas. It is a native of the West 
Indies and occurs sparingly in Louisiana and Florida. The 
larva^ are bluish green in color with the head pale yellow, and 
when mature are almost an inch in length. The caterpillars 
feed on the foliage and fold the leaves, thus making a retreat 
within which the larva lives and within which it spins its cocoon. 
The pupa is dark brown and about f inch in length. The moth 
has an expanse of about an inch and is light yellow in color. 
The front and outer edge of the front wdngs are grayish brown. 
There is a nearly straight brown line across the base of the 
front wing and a wavy line of the same color three quarters 
the distance from the base on both wings. There are two 
black spots near the front margin of the front wing and one 
on the hind wing. There are several generations annually, 
about twenty-five days being required for the completion of 
the life cycle. 

This sweet potato pest may be controlled by spraying the 

vines with arsenate of lead (paste), 4 pounds in 50 gallons of 

water. ^ 

Reference 

U. S. Dept. Agr. Bull. G09. 1917. 



242 MANUAL OF VEGETABLE-GARDEN INSECTS 

The Sweet Potato White-Fly 

Bemisia inconspicun Quaintance' 

In southern Florida sweet potatoes, especially the late crop, 
are often subject to very serious injury by this species of white- 
fly, which in general appearance is similar to the common green- 
house white-fly. The eggs are deposited on the underside of 
the leaves and hatch in about a week. The nymphs are often 
abundant enough nearly to cover the entire under surface of 
the leaf, sucking out the sap and sometimes killing the plant. 

This white-fly may be controlled by one or two applications 
of soap solution or kerosene emulsion applied to the underside 
of the leaves. 

Other Sweet Potato Insects 

Garden web worm : 18 
Nezara viridula : 43 
Yellow bear caterpillar : 357 
Carrot beetle : 185 
Potato aphis : 150 
Garden flea-hopper : 77 
Dark-sided cutworm : 268 
Striped cutworm : 270 
Dingy cutworm : 271 
Clay-backed cutworm : 274 
Variegated cutworm : 276 
Army-worm : 288 
Fall army-worm : 292 
Ash-gray blister-beetle : 306 
Pale-striped flea-beetle : 321 
Sweet potato flea-beetle : 332 
Root-knot nematode : 338 
Corn and cotton wireworm : 349 



CHAPTER XIII 
ONION INSECTS 

Onions are subject to attack by a relatively small number 
of insects. The most important of these are the onion maggot 
and the onion thrips, but occasionally cutworms and wire- 
worms may cause serious loss. 

The Onion Maggot 

Phorbia ceparum Meigen 

In Europe and America, onions are often severely injured 
by the attacks of a small white maggot that feeds on the under- 
ground stem or in the bulb. The maggots may attack and 
destroy the plants soon after the seeds have germinated, and 
the failure to obtain a stand is, therefore, often attributed to 
poor seed. 

The flies appear in the onion fields in the spring and the 
female deposits her smooth, white, elongate oval eggs, which 
are slightly grooved on one side and about -it inch in length, 
in the base of the leaf-sheath, on the side of the stem near the 
ground, and in cracks and crevices of the soil. The eggs hatch 
in three to ten days and the young maggot works its way 
down along the stem, usually within the sheath. If the plant 
is very young, the maggot may so injure the stem that the 
whole top dies. When the plants are older, the maggots bur- 
row into the bulb and cause decay to develop. Several maggots 
are often found in a single bulb. The full-grown maggot is 
nearly I inch in length, smooth, and dull whitish in color. The 

243 



244 MANUAL OF VEGETABLE-GARDEN INSECTS 

maggot is largest at the hind end of the body and tapers to a 
point at the head. Posteriorly the body is obliquely truncate. 
The flat surface is surrounded by a row of twelve fleshy tubercles, 
of which the middle lower pair are single-pointed and not two- 
toothed as in the case of the cabbage root-maggot. In the 
onion maggot, in addition to the two tubercles just back of the 
vent, there are two smaller ones on the ventral side just in 
front of the two large ventral marginal tubercles ; they aid the 
larva in crawling. 

The maggots become full-grown in two to three weeks in 
green onions. In second-year onions, they develop more slowly 
and sometimes require four or five weeks to reach maturity. 
When full-grown, they transform to pupse within the hardened 
larval skin or puparium, generally in the ground surrounding 
the plant; sometimes the transformation takes place within 
the bulb. The puparium resembles a grain of wheat in form, 
is of a chestnut brown color and about j inch in length. The 
flies closely resemble those of the cabbage and seed-corn mag- 
gots but the males may be separated by the characters given 
in Fig. 26. They emerge from the puparia in about two 
weeks and lay eggs for another brood. There are at least two 
or three broods annually. The insect hibernates principally 
in the form of puparia, but both maggots and flies some- 
times survive the winter. 

Control. 

The onion maggot has been found rather difficult to control. 
Carbolic acid emulsion applied as described under cabbage 
root-maggot, page 33, has been found of some value for killing 
the eggs and young maggots. Clean cultivation and rotation 
of crops are widely recommended to prevent maggot attack. 
Recent experiments in Wisconsin have shown, however, that 
since the flies require from ten days to two weeks after emer- 
gence in which to mature their eggs for deposition, the insects 



ONION INSECTS 245 

can be more easily and satisfactorily controlled by killiniij them 
with a sweetened poison spray. The most satisfactory results 
have been obtained by using the following formula : 

Sodium arsenite | ounce 

Water 1 gallon 

Molasses 1 pint 

This material should be sprinkled over the plants and sur- 
rounding soil when the flies first appear so that they may be 
killed before laying their eggs. The application should be 
repeated at intervals of a week, or oftener during rainy seasons. 

References 

Cornell Agr. Exp. Sta. Bull. 78, pp. 495-496. 1894. 

N. J. Agr. E.xp. Sta. Bull. 200. 1907. 

Conn. Agr. Exp. Sta. Rept. for 1911, pp. 286-292. 

Severin and Severin, Jour. Ee. Ent., 8, pp. 342-350. 1915. 

The Onion Thrips 

Thrips labaci Lindeman 

Onions are subject to injury by- a small yellowish thrips 
which punctures the epidermis of the leaves, sucks out the 
juices and causes the plants to turn whitish, wilt and fall down. 
This trouble is known among onion-growers as white blast. 
The onion thrips is almost cosmopolitan in its distribution, 
occurring in Europe, North America, South Africa and Aus- 
tralia. In the United States it has been reported from nearly 
all parts of the country and is present in southern Canada. 
In some seasons this insect is the most serious enemy of the 
onion crop on the muck lands of New York, Ohio and Indiana 
and in the Bermuda onion regions of Texas. It sometimes 
seriously infests cabbage and cauliflower and is found on many 
wild and cultivated plants including cucumber and melon. 
In Europe it is a serious enemy of tobacco. 



246 MANUAL OF VEGETABLE-GARDEN INSECTS 




Fig. 148. — The onion thrips, adult 
female (X 30). 



The onion thrips passes the winter in both the adult and 
nymphal state on onion plants left in the field. It is also 

probable that the thrips 
hibernates in the rubbish 
around the edge of the field, 
since the infestation usually 
begins along the weedy 
borders and gradually 
spreads over the remainder 
of the field. 

The adult female thrips 
(Fig. 148) is about -^ inch 
in length and varies from 
light yellow to brownish 
yellow in color. The wings are long and narrow and bear on 
the hind margin a fringe of long hairs. The male is rarely 
found and the females normally reproduce with- 
out being fertilized. The egg is translucent 
white, irregularly bean-shaped and about xio' 
inch in length. It is inserted nearly its full 
length into the tissue of the leaf; the tip of 
the smaller end projects slightly above the 
surface. The eggs hatch in five to ten days, 
the longer period being the more common. 
The newly hatched nymph is about tu inch in 
length and translucent white in color with the 
eyes bright red (Fig. 149). After feeding, the 
body assumes a greenish color from the ingested 
food. The first stage lasts about two days but in 
some cases the period is longer. In the second 
stage, the insect is about ^V inch in length and 
varies in color from pale yellow to lemon-yellow 
(Fig. 150). These second-stage nymphs complete their growth 
in about ten days after hatching ; they then leave the plant and 




Fig. 149. — The 
onion thrips, 
first stage 

nymph (X 75). 



ONION INSECTS 



247 



enter the ground a short distance, where, by twisting and turning 
their bodies, they construct small earthen cells. In these cavities 
the insects molt and thus enter the third nymphal, or so-called 
prepupal, stage. These third-stage nymphs are yellowish 
white in color and the wing-pads extend to the middle of the 
second abdominal segment. They do not feed in this stage 
but remain quietly resting in their earthen cells. 
They are able to walk, however, and when 
disturbed soon crawl into hiding again. In 
two or three days the insect molts and enters 
the fourth and last nymphal stage (sometimes 
known as the popular stage). The fourth stage 
is whitish in color and the wing-pads extend 
to the eighth abdominal segment ; the body 
is more spiny than in the preceding stages. In 
this stage, which lasts from one to six da^'s, the 
insect remains in a quiescent condition and 
takes no food. At the next molt the thrips 
becomes adult, returns to the plant and re- 
sumes feeding. The life cycle is completed 
in about twenty-six days. There are five or 
six generations annually and breeding con- 
tinues until stopped by cold weather. 

A careful examination of infested onion plants at any time 
during the summer will disclose the presence of four stages of 
the onion thrips, viz., eggs, first- and second-stage nymphs, 
and winged adult females. The first- and second-stage nymphs 
may be distinguished by the difference in size and by the more 
distinctly yellow coloration of the latter. Both the nymphs 
and adults feed on all parts of the leaves but are to be found in 
greatest numbers hidtlen under the sheath at the base of the 
leaves or between the young leaves at the center of the plant. 
In feeding, the thrips punctures the epidermis of the leaf with 
its sharp needle-like mouth-parts and then sucks out the juices 




Fig. 150. — The 
onion thrips, 
second stage 
nymph (X45). 



248 MANUAL OF VEGETABLE-GARDEN INSECTS 

of the plant, killing the cells and causing them to turn whitish. 
When the infestation is severe and the punctures consequently 
very numerous and close together, the leaves lose their dark 
green color and assume a dirty white or bleached appearance. 
The tender leaves at the center of the plant do not turn white 
when punctured by the thrips, but instead curl inward and 
downward and present a thickened deformed appearance. 

Badly injured plants wilt and the leaves fall over on the 
ground ; in such cases, the bulbs do not make the proper 
growth and the crop is of small size and inferior in quality. 
The plants are most susceptible to injury by thrips during 
June and July when they should be making their most rapid 
growth. Thrips are most destructive in years of drought 
because, under unfavorable conditions, the plants are less able 
to outgrow the injury. Onions grown on poor soil or when 
poorly cultivated are more likely to be injured by thrips than 
when planted on good ground and well cared for. When 
onions are grown for seed the thrips often infest the flower- 
heads in sufficient numbers greatly to reduce the crop. 

Infested cabbage and cauliflower leaves turn brownish or 
rusty instead of dirty white, as in the case of onions. As a 
rule the injury is confined to the outer leaves, and is usually 
outgrown by the plants, provided other conditions are favorable. 

Control. 

Onion thrips can be killed by application of such contact 
insecticides as whale-oil soap, kerosene emulsion and tobacco 
extracts. The best results have been obtained by spraying 
early, before the leaves turn down, with "Black Leaf 40" 
tobacco extract, 1 pint in 100 gallons of water in which there 
have been dissolved 5 pounds of soap. There are great difficul- 
ties in applying the spray to large fields ; heavy traction or 
power sprayers cannot be employed on the soft muck soil on 
which onions are usually grown. The knapsack sprayer can 



ONION INSECTS 249 

be used in the small onion patch but its use is too laborious 
and expensive to be practical in the large commercial onion 
field. To be effective, a considerable quantity of the liquid 
must be utilized thoroughly to wet the plants and a strong 
spray is needed to force the material down into the sheaths of 
the leaves and between the tender leaves at the center of the 
plant. Some better method of applying is needed in order to 
make spraying for the onion thrips a practical success under 
commercial conditions. 

References 

N. Y. (Geneva) Agr. Exp. Sta. Bull. 8.3, pp. 680-683. 1894. 

Ha. Agr. Exp. Sta. Bull. 46, pp. 10.3-114. 1898. 

J. C. Faure, Unpublished thesis, Cornell University Library. 

The Barred-Winged Onion Fly 

Chcetopsis aenea Wiedemann 

Onions are occasionally injured by a yellowish or whitish 
maggot about \ inch in length, that burrows in the bulbs, 
causing decay to ensue. The maggots of this insect have also 
been found injuring corn, wheat, oats, sorghum and sugar- 
cane and have been reared from the common reed. The larvae 
have also been recorded as parasitic on the common stalk- 
borer and on a lepidopterous borer in cat-tail. The insect is 
native to America and ranges throughout the eastern United 
States from Canada to the West Indies. The fly is about ts 
inch in length with the head grayish and the thorax and abdo- 
men metallic green. The wings are whitish crossed by three 
broad brown bands. The life history of this insect has been 
studied on oats. The female deposits her minute, elongate, 
pointed white eggs just under the edge of the leaf-sheath, 
singly or in groups of two to five. The maggots work down 
inside the leaf-sheath where, when mature, they transform 
into polished brown puparia about ^ inch in length. In 



250 MANUAL OF VEGETABLE-GARDEN INSECTS 

Michigan the maggots were found to winter in the onions. 
There are said to be three or four broods annually. 

References 

Insect Life, 7, pp. 352-354. 1895. 

Mich. Agr. Exp. Sta. Bull. 200, pp. 206-208. 1902. 

The Black Onion Fly 

Tritoxa flexa Wiedemann 

Occasionally associated with the insect last treated are found 
the maggots of another fly. This species is native to America 
and ranges through the northern states from New Jersey to 
Minnesota. The fly is ts inch in length and dull black in color. 
The wings are dull brown marked with three oblique whitish 
bands. There are thought to be two broods annually. The 
maggots sometimes continue to work in stored onions, reduc- 
ing them to mere shells. 

No satisfactory control for this onion pest is known. 

Other Onion Insects 

Cabbage web worm : 16 
Seed-corn maggot : 36 
Yellow bear caterpillar : 357 
Sugar-beet webworm : 97 
Belted cucumber beetle : 115 
Garden springtail : 139 
Bean aphis : 76 
Spotted cutworm : 262 
Greasy cutworm : 265 
Dark-sided cutworm : 268 
Striped cutworm : 270 
Clay-backed cutworm : 274 
Black army-worm : 275 
Variegated cutworm : 276 
Army cutworm : 287 
Beet army-worm : 294 
Black blister-beetle : 307 
Root-knot nematode : 338 



CHAPTER XIV 

INSECTS INJURIOUS TO MINOR VEGETABLE CROPS 

The crops treated in this chapter — rhubarb, okra, salsify, 
pepper, water-cress and lettuce — are not, as a rule, seriously 
injured by insects and the control of these pests is of less im- 
portance in the culture of these vegetables than in the case of 
those previously treated. 

Rhubarb 

Rhubarb is not usually seriously affected by insects. Its 
most important enemies are the rhubarb curculio, the hop 
flea-beetle, the spinach aphis, the bean aphis and certain species 
of cutworms. 

The rhubarb curcuHo, Lixus concavus Say 

The leaf-stalks of rhubarb are often injured by the feeding and 
.egg-laying punctures of a rather large black, yellow-dusted 
snout-beetle. The sap exudes from the wounds and collects 
as glistening drops of gum. Fortunately the eggs do not hatch 
when deposited in rhubarb but are killed by the flow of sap. 
This insect ranges from New England to Idaho and southward 
to Florida and Louisiana. 

The beetle (Fig. 151) is about ^ inch in length and black in 
color dusted with a yellowish covering which easily rubs off. 
The head is provided with a curved snout on the end of which 

251 



252 MANUAL OF VEGETABLE-GARDEN INSECTS 

the mandibles are borne. The insect passes the winter usually 
in the adult stage hidden away in dry sheltered places. The 
adults appear in the spring and are often seen resting on the 
stems and foliage of rhubarb and dock. They feed on the edge 
of the leaves and puncture the stems with their beaks. The 
female deposits her eggs singly in cavities about i inch deep 
in the stalks of dock, sunflower, thistle and in the leaf-stems and 
flower-stalks of rhubarb. The eggs are oblong oval, yellowish 
white in color and about ^e hich in length. They hatch in a 
week or ten days when deposited in their wild food plants but, 
as previously stated, are not able to develop in rhubarb. On 
hatching the larva burrows down through the stalk so that 

when it reaches maturity it occu- 
pies a cavity just below the surface 
of the ground. Although many 
eggs are often laid in the same 
stem, usually only one grub reaches 
Fig. 151. — The rhubarb maturitv. The full-grown larva is 

curcuho(X2i). ' u ^ •? • -u • 

a rootless grub about -f incn in 
length and is white with a brownish head. As the eggs are 
laid over a considerable period from the first of June till the 
middle of July, the grubs do not reach maturity at the same 
time. The larval period occupies, on an average, eight or 
nine weeks. In New Jersey the greater number are mature 
by the middle of August. The pupa is white, about ^ inch 
in length, and is found in a rather large cavity in the crown 
of the plant just below the surface of the ground. The pupal 
period occupies a little over a week. After transformation 
the beetle remains in the pupal chamber for several days until 
fully hardened and then gnaws its way out and after feeding a 
short time goes into hibernation. There is only one generation 
annually. 

The beetles are easily seen resting on the plants and may be 
readily captured and destroyed by hand. All wild plants in 




INJURIOUS TO MINOR VEGETABLE CROPS 253 

which the beetles breed should be destroyed in the vicinity of 
rhubarb beds or a few dock plants may be left growing as a 
trap in which the beetles will deposit their eggs, when they 
should be destroyed before the grubs reach maturity. 

References 

U. S. Div. FaiU Bull. 23, pp. 61-69. 1900. 
Weiss, Jour. Econ. Ent. 5, pp. 434-436. 1912. 

Other rhubarb insects 

Southern corn root-worm : 222 
Yellow bear caterpillar : 357 
Spinach aphis : 105 
Common stalk-borer : 157 
Burdock borer : 160 
Bean aphis : 76 
Spotted cutworm : 262 
Striped cutworm : 270 
Variegated cutworm : 276 
Army cutworm : 287 
Hop flea-beetle : 335 

Okra 

The insect enemies of okra are not numerous. The pods are 
often attacked by the corn ear-worm and the buds and leaves 
are injured by the caterpillar of the gray hair-streak butterfly. 
The plants are also attacked by the spinach aphis and melon 
aphis and are often defoliated by the okra caterpillar. 

The okra caterpillar, Anomis erosa Hiibner 

Okra and roselle are likely to be defoliated by a green looping 
caterpillar related to the cotton worm. This insect also feeds 
on several species of hibiscus, abutilon, hollyhock and on 
Urena lobata and is occasionally found on cotton. It ranges 
throughout the southern United States, the West Indies, 



254 MANUAL OF VEGETABLE-GARDEN INSECTS 

South Africa, Madagascar, Mauritius, the Oriental region and 
Austraha. 

The moth has an expanse of It to li inches. The front wing 
has the outer margin angled at the middle. The basal half is 
yellow usually shaded with light brown and the outer half is 
light pinkish brown often shaded with yellow. The hind wings 
are pale yellow shading into ocher yellow towards the outer 
border. The moth deposits her pale green, globular, slightly 
flattened eggs singly on both the upper and under side of the 
leaves. The egg is about -^ inch in diameter and marked with 
a series of ridges radiating from the apex. The eggs hatch in 
about four days and the young caterpillar, after eating its 
egg-shell, begins feeding on the leaf in which it eats out small 
holes. The larger larvae eat out irregular areas from the 
side of the leaf and when abundant often defoliate the plant. 
The caterpillar passes through seven stages in the course of its 
development and reaches maturity in about twenty-four days 
in warm weather. It is then about If inches in length, pale 
pea-green in color, inconspicuously marked with five narrow 
broken yellow lines above and with a broader yellowish white 
stripe on each side. While young the caterpillars suspend them- 
selves by a thread when disturbed and are able to climb back 
to the plant when the danger has passed. They walk with a 
peculiar looping motion owing to the fact that only four pairs 
of prolegs are present on the abdominal segments. When full- 
grown the caterpillar transforms in a folded leaf into a blackish 
brown pupa about f inch in length and in five days to two 
weeks depending on the season the moths emerge. In Florida 
the life cycle requires nearly five weeks. 

The caterpillars can be killed by spraying with arsenate of 
lead (paste), 2 pounds in 50 gallons of water. Recent experi- 
ments also indicate that effective work against the caterpillars 
can be done by spraying with " Black Leaf 40 " tobacco ex- 
tract, 10 ounces in 100 gallons of water in which 5 or 6 pounds 
of soap have been dissolved. 



INJURIOUS TO MINOR VEGETABLE CROPS 255 

References 

Riley, Rept. U. S. Ent. for 1881 and 1882, pp. 167-170. 

U. S. Bur. Ent. Bull. 126. 1913. 

Dozier, Jour. Econ. Ent. 10, i)p. 536-542. 1917. 

Other okra insects 
Spinach aphis : 105 
Corn ear- worm : 211 
Stink-bugs: 232 
Harlequin cabbage bug : 38 
Green soldier-bug : 42 
Nezara viridula : 43 
Striped cucumber beetle : 109 
Belted cucumber beetle : 1 15 
Melon aphis : 135 
Gray hair-streak : 84 
Semi-tropical army-worm : 297 
Red-spider : 351 

Salsify 

The insects affecting salsify have not been carefully studied 
and those that have been listed as injurious to this plant are, 
as a rule, general feeders and have not been recorded as causing 
any serious injury to this crop. The following insects treated 
untler other crops have been reported as attacking salsify : 

Yellow bear caterpillar : 357 
Tarnished plant-bug : 192 
Yellow-striped army-worm : 295 
Root-knot nematode : 338 

Pepper 

Peppers are subject to attack by a number of insects that 
infest the potato, especially flea-beetles and the spinach aphis 
and potato aphis. 

The pepper weevil, Anthotwmus eugenii Cano 

In southern Texas and Mexico peppers are sometimes seri- 
ously injured by a small shining blackish or reddish black snout- 



256 MANUAL OF VEGETABLE-GARDEN INSECTS 

beetle with a brassy luster, tV to | inch in length. The weevils 
are injurious in late summer and fall. In feeding they punc- 
ture the buds and young fruits with their beaks and the female 
deposits her small white oval eggs, about gV i»ch in length, in 
the cavities so made. The eggs hatch in two to four days and 
the young grubs feed on the surrounding tissue. The injured 
buds are blasted and the infested fruits usually drop pre- 
maturely. The grubs become mature in about two weeks. 
They are then about ^ inch in length, white and strongly curved. 
When about to pupate, the larva constructs a cell of excrement 
and bits of decayed tissue inside the fruit. The pupa is light 
amber in color, about ^ inch in length and rather robust in 
form. From six to ten days are spent in this stage. Soon after 
transformation the beetle leaves the pupal cell but remains 
within the fruit until thoroughly hardened, when it gnaws out 
an exit hole through the pod. 

The pepper weevil may be controlled by collecting and 
burning all infested fruits once a week during the egg-laying 
period of the weevils. It is not advisable to grow peppers 
year after year on the same land. In Mexico spraying with 
paris green is said to have been found of some value for the 
control of this pest. 

References 

U. S. Bur. Ent. Bull. 54, pp. 43-48. IQOf). 
U. S. Bur. Ent. Bull. 03, pp. 55-58. 1907. 

Other pepper insects 

Corn ear- worm : 211 

Serpentine leaf-miner : 46 

Spinach aphis : 105 

Southern leaf-footed plant-bug : 121 

Tomato worm : 168 

Nezara viridula : 43 

Belted cucumber beetle: 115 

Colorado potato beetle : 142 



INJURIOUS TO MINOR VEGETABLE CROPS 257 

Potato aphis : 150 
Common stalk-borer : 157 
Garden flea-hopper: 77 
Army-worm : 288 
Semi-tropical army-worm : 297 
Potato flea-beetle- 314 
Western potato flea-beetle : 318 
Root-knot nematode : 338 
Red-spider : 351 

Water-Cress 

Owiii<i; to its semi-aquatic habit water-cress is comparatively 
free from insect attack. In certain localities its most serious 
enemy is a small crustacean, the water-cress sowbug. 

The water-cress sowbug, Mancasellus brachyurus Harger 

In the eastern United States water-cress is often seriously 
injured by an aquatic species of sowbug that attacks the sub- 
merged portions of the plant, cuts off the roots and stems and 
causes large masses of the cress to float on top of the water. 
This form differs from the species found in greenhouses by hav- 
ing longer legs and antennae and being shrimp-like in form 
when viewed from the side. It is about ^ inch in length and 
gray in color. It often occurs in immense numbers so as to 
destroy practically the whole crop. 

Where cress is grown in natural streams or ponds, no prac- 
tical method of controlling the sowbugs has been devised. 
Some growers, however, have been able to o\'ercome the dif- 
ficulty by growing the plants in broad shallow beds sloping to- 
wards the center, where a trough ten inches square lined with 
boards extends the whole length of the bed. When the sow- 
bugs become abundant, the water is shut off for twelve to 
twenty-four hours allowing the beds to drain. Water is re- 
tained in the trough, in which the sowbugs soon accumulate in 
great numbers. Thev mav be destroved bv the addition of 



258 MANUAL OF VEGETABLE-GARDEN INSECTS 

a liberal quantity of copper sulfate solution. Less injury will 
result to the plants if the water is drained off soon after the 
cress has been gathered. 

Reference 

U. S. Bur. Ent. Bull. 66, pp. 11-15. 1907. 

Tlie water-cress leaf-beetle, Phadon aruginosa Suffrian 

In the eastern United States water-cress is occasionally in- 
jured by the larvae and adults of a small shining, bronzy black 
leaf-beetle about | inch in length. The life history of this 
insect is very imperfectly known. The full-grown larva is 
about i inch in length ; the head is shining black and the re- 
mainder of the body is brownish black, lighter between the 
segments and below. Its body is provided with numerous 
prominent tubercles from which hairs arise. Both larvae and 
adults feed on the underside of the leaves. 

No satisfactory method of controlling this pest has been 

devised. 

Other water-cress itisects 

Diamond-back moth : 12 

Spinach aphis : 105 

Striped cabbage flea-beetle : 324 

Lettuce 

The most important insect enemies of lettuce are the cab- 
bage looper, the celery looper and several species of cutworms. 
Several kinds of plant-lice infest the plants and are especially 
troublesome in greenhouses. Slugs and millipedes often at- 
tack the crop, sometimes causing considerable damage. 

The lettuce root-louse, Rhizohius lactuca Fitch 

The roots of lettuce are often infested by a yellowish wing- 
less plant-louse about ^ inch in length which has the body 



INJURIOUS TO MINOR VEGETABLE CROPS 259 

duster! with a whitish powder and bears tufts of white waxen 
threads. The insects often occur in dense masses on the roots 
and may retard the jijrowth of the plant. They are attended 
by ants and are probably carried by them to new feeding 
grounds. The life history of this species is \'ery imperfectly 
known and its wild food plants ha\'e not been determined. 

The lettuce root-louse rarely causes enough injury to warrant 
repressive measures. 

Reference 
Fitch, 14th Rept. State Ent. N. Y., pp. 360-363. 1870. 

Other lelluce insects 

Cabbage loopor : S 

Garden webwonn : 1<S 

Turnip aphis : 27 

False (3hineh-bug : 47 

Celery looper : 101 

Spinach aphis : 10.5 

Western twelve-spotted cucumber beetle: 114 

Belted cucumber beetle: 115 

Garden springtail : 139 

Bean thrips : 69 

Garden flea-hopper : 77 

Dark-sided cutworm : 268 

Striped cutworm : 270 

Variegated cutworm : 276 

Glassy cutworm : 279 

Yellow-headed cutworm : 281 

Spotted-legged cutworm : 282 

Clover cutworm : 284 

Pale-striped flea-beetle : 321 

Root-knot nematode : 338 

Millipedes: 342 

Slugs: 354 



CHAPTER XV 
CUTWORMS AND ARMY-WORMS 

Of all general crop pests, none is more ubiquitous nor per- 
sistent in its attacks on truck crops than a group of cater- 
pillars of Noctuid moths which has received the name of cut- 
worms or army-worms. Under favorable circumstances, almost 
any cutworm may become so abundant as to migrate from field 
to field in so-called armies devouring practically every green 
thing in its path. The name army-worm, however, has been 
restricted to two or three species in which the tendency to 
adopt this habit has been highly developed. 

Cutworms are smooth, nearly naked caterpillars varying in 
length from 1 to 2 inches when full-grown, usually dull colored 
and indistinctly marked with spots and longitudinal stripes. 
The name cutworm has been well applied to these caterpillars 
because of the habit of many species of cutting off succulent 
plants near or just below the surface of the ground. Cut- 
worms feed mostly at night and spend the day either in a 
burrow in the soil or under the protection of stones and rubbish 
near their food plants. Some species rarely come to the sur- 
face at all but feed on the roots and underground stems. 
Others, however, have the habit of climbing shrubs and trees 
to feed on the buds, foliage and even the fruit. Species possess- 
ing this habit to a marked degree are sometimes known as climb- 
ing cutworms. 

When mature, cutworms transform through brownish pupjfi 
into dull-colored, rather heavy-bodied moths. The wings are 
marked with bands and spots which for convenience in 

260 



CUTWORMS AND ARMY-WORMS 



261 



description have received the names indicated in Fig. 152. 
They are active only at night and many species are at- 
tracted to lights and to sugar baits. A large proportion 
of the moths which fly into our rooms in summer evenings 
belong to this family. Their glowing eyes and heavy tufts of 
scales and hairs on the thorax together with their nocturnal 



TraTisverse dnterior 



Reniform 



Transverse posterior 
Subterminal 




iTerTnindl 



lC?dvifor?7i 



Fio. 1.52. — Diugruiu of the wing-pattern of a cutworm moth. 



habits have given them the name of owlet moths. They are 
rarely seen by day, being hidden away in sheltered places, as 
under the loose bark of trees, in board piles and in crevices of 
fences. 

The species treated in this chapter are those which have 
caused outbreaks of sufficient importance to attract the atten- 
tion of entomologists. It is quite probable that other species 
may ha\'e been concerned but so far have escaped detection. 
These may at any time become so abundant as to cause serious 



262 MANUAL OF VEGETABLE-GARDEN INSECTS 

damage. In this account all the more important facts known 
regarding each species are presented but much remains to be 
learned of their habits and life histories. Here is a fruitful 
field of investigation which warrants more attention than it 
has received in the past. 

The Spotted Cutworm 
Noctua c-nigrum Linnaeus 

In the northern United States and Canada the spotted cut- 
worm is one of the most common and troublesome species. 
It is generally distributed throughout the northern hemisphere. 
In Asia it is found as far south as northern India; it ranges 
throughout all of Europe and in North America is most abun- 
dant in the northern United States and Canada and has been 
reported from Mexico. This cutworm is a general feeder attack- 
ing cabbage, tomato, turnip, potato, celery, rhubarb, onion, 
pea, beet, carrot, mangel, corn, grasses, clover, violet, ferns, 
lobelia, helianthus and chicory. As a climber it is reported as 
injurious to the tips and buds of cranberry in Massachusetts ; 
it also feeds on currant and gooseberry. The caterpillars of 
the July brood sometimes injure the fruit of the tomato. In 

years of great abundance 
they may assume the army- 
worm habit. 

Fig. 153. — The spotted cutworm So far aS knOWn, the 

^ ^ spotted cutworms pass the 

winter as partly grown caterpillars. They become mature in 
early spring. The larva is 1^ inches in length, of a pale brownish 
to ashy gray color. This species may be easily recognized by 
a double row of oblique triangular black spots on the dorsal 
surface of the abdominal segments. These spots increase in 
size and distinctness towards the posterior end of the body 
(Fig. 153). On the side there is a more or less distinct dark 



CUTWORMS AND ARMY-WORMS 



263 



stripe running through the spiracles below which the color is 
decidedly lighter than above. Pupation takes place in the 
ground. The pupa is f inch in length and of a dark mahogany 
brown. The pupal period varies from two to four weeks. 

The moths are on the wing from late May to October and 
apparently belong to two overlapping broods. The moth 
has an expanse of 1^ to 2 inches (Fig. 154). The front wings 
are rich purplish to reddish brown. The kidney-shaped spot 
is usually tinged with reddish. From this spot there extends 
towards the base of the 
wing a black bar deeply 
incised by a triangular 
light area which often 
extends to the front margin 
of the wing. The hind 
wings are smoky, darker 
along the outer margin. 

The moth deposits her 
eggs singly, in rows, or in 
compact clusters of 200 or 
more on leaves. The egg is hemispherical in shape, strongly 
ribbed, almost transparent and is about ^ inch in diameter. 
There are probably two generations annually. 




Fig. 154. 



The spotted cutworm moth 
(iiiitunil size). 



References 

U. S. Div. Ent. Bull. 27, pp. .54-.59. 1901. 
Dept. Agr. Canada Ent. Bull. 10, pp. 23-24. 



1915. 



The Well-^Iarked Cutavorm 
Noctua clandestina Harris 

This cutworm is distributed from Nova Scotia to IVIissouri 
and Colorado, and northward. It also occurs in Greenland 
and Kamchatka. It has been reported as injuring the follow- 
ing crops : corn, buckwheat, wheat, cabbage, cauliflower, bean, 



264 MANUAL OF VEGETABLE-GARDEN INSECTS 



pumpkin and other vegetables. As a climbing cutworm, it 
attacks apple, currant and gooseberry. Among its wild food 
plants are included soft maple, box elder and wild endive. 

These insects hibernate as partly grown caterpillars which 
become mature during May and June. The caterpillar is If 

inches in length and is 



Fig. 155. 



The well-marked cutworm 
(X U). 



easily recognized by a double 
row of distinct, oblique, 
black spots on the back 
of the abdominal segments 



(Fig. 155). The rows of black spots are bordered laterally 
by a distinct yellow stripe. The median yellowish stripe 
is distinct. The reddish brown pupte are found buried 
a few inches in the soil. The moths emerge during June and 
July and have been collected as late as the middle of October. 
During the day they have the habit of hiding under loose 
bark, in crevices about buildings 
and in fences. When at rest the 
wings are folded closely one above 
the other, giving the moth a flattened 
appearance. The moth has an ex- 
panse of li inches. The front 
wings are of a dark, smoky brown 
color, the transverse lines paler 
and not very distinct. The inner 
spot is oval bordered with black ; the reniform spot is marked 
with black on the inner side and the two are often united by 
a black line. The hind wings are smoky, darker towards the 
margin (Fig. 156). The eggs have not been described. So 
far as known, there is only a single generation annually. 




Fig. 156. — The well-marked 
cutworm moth (natural size). 



References 

Harris, Insects Injurious to Vegetation, pp. 32.5-327. 
Cornell Agr. Exp. Sta. Bull. 104, pp. 571-574. 1895. 



1841. 



CUTWORMS AND ARMY-WORMS 265 

The Greasy Cutworm 

Agrotis ypsilon von Rottenburg 

The greasy cutworm is cosmopolitan in distribution, occurring 
in injurious numbers in Europe, Asia, Africa, North and South 
America, Austraha, New Zealand, the East Indies and Hawaii. 
The caterpillar is a general feeder. Its food plants include 
many wild species and the following cultivated crops : corn, 
grasses, potato, tomato, cabbage, beet, eggplant, spinach, bean, 
squash, cauliflower, cucumber, radish, asparagus, onion, straw- 
berry, tobacco and cotton. In the United States and Canada 
this cutworm is usually abundant, though on the whole not so 
injurious as some of the other species. 

Owing to the wide distribution of the insect, including many 
life zones, its seasonal history presents many variations. In 
North America, hibernation occurs in either the larval or pupal 
stage. In Florida all stages of the larvje have been found 
during mild winters and in Texas and Georgia moths have 
•been reared from pupae plowed up in cotton fields during the 
winter. It is quite probable that in the northern United States 
and Canada hibernation takes place most commonly in the 
larval stage, though wunter pupjie have been recorded from 
Illinois. 

The moths emerge over a considerable period, from June to 
October, being most abundant in Jul>' and August. The 
moth has an expanse of li to nearly 2 inches. The front 
wings are dark brownish gray varying to dark brown, with 
the apical third lighter in color and are crossed by a diagonal 
light band in which are two black elongate spots. Near the 
outer margin of the dark area is a characteristic U-shaped black 
mark with a black dash extending from its outer side. The 
hind wings are light brownish gray with a pearly luster; the 
A'eins are brown (Fig. 157). From July to September the 
females deposit their eggs in small clusters on the leaves or 



266 MANUAL OF VEGETABLE-GARDEN INSECTS 



stems of plants, usually near the ground. Each female may lay 
from 200 to 400 eggs. The egg is dome-shaped, about t^ inch 
in diameter, and creamy white when laid, becoming darker 
before hatching. At the top there is a slight depression from 
which radiate many ridges extending to the base of the egg. 

In Illinois, eggs laid in July were observed to hatch in twenty- 
two days, while in Hawaii they hatch in only two or four days. 
The young caterpillars are pale green, the black tubercles on 
the segments showing prominently. Later the pale longitudinal 
stripes become evident. When full-grown the caterpillar is li 
to If inches in length, of a nearly uniform dark greasy gray 

color with an indistinct mid- 
dorsal yellow line and two 
faint lateral stripes. It is 
dark greenish yellow be- 
neath. In the summer the 
caterpillars require at least 
a month to reach maturity. 
They are voracious feeders 
and have developed to a 
high degree the habit of 
cutting off tender plants and 
dragging them to their burrows. They feed mostly at night 
and during the day remain hidden in burrows an inch or so 
from the surface of the ground. 

The mature caterpillars transform in earthen cells a short 
distance below the surface into brownish pupse about f inch 
in length. Observations in Canada indicate that the length of 
the pupal period in late summer is about three weeks, while in 
Illinois in early summer it is four weeks ; in Hawaii the pupal 
period is ten days to three weeks. 

In Canada there are two broods annually, the larvae of the 
second brood hibernating in a partly grown condition. This 
is probably general for the northern United States and Canada, 




Fig. 157. 



The greasy cutworm moth 
(natural size). 



CUTWORMS AND ARMY-WORMS 267 

though undoubtedly exceptions occur since pupie of the first 
brood may not transform the same season. 

References 

Riley, Rept. U. S. Ent. for 1884, pp. 294-295. 

Forbes, 23rd Rept. State Ent. 111., pp. 21-23. 1905. 

Hawaii Sugar Planters' Exp. Sta. Div. Ent. Bull. 7, pp. 19-21. 1909. 

Dept. Agr. Canada Ent. Bull. 10, pp. l(i-17. 1915. 

The Red-Backed Cutworm 

Paragrotis ochrogaster Guenee 

This destructive cutworm ranges from Nova Scotia to British 
Columbia southward to Colorado and Missouri. It is more 
abundant in the northern part of its range, being the most 
injurious species throughout Canada. The larva is almost 
omnivorous in its tastes, attacking any succulent plant, especially 
cabbage, cauliflower, beet, radish and many annuals of the 
flower-garden. It is a serious pest in the \Yest to grain crops, 
particularly oats, wheat and barley. This species may be dis- 
tinguished from other common cutworms by the reddish color 
of the upper surface of the body. 

In eastern Ontario, the red-backed cutworm has been found 
to hibernate in both the egg and larval stages. The over- 
wintered eggs hatch the latter part of April and the caterpillars 
become mature in about seven weeks. In its feeding habits it 
resembles the greasy cutworm. The mature caterpillar is 1^ 
inches in length, reddish above with a pale median stripe; 
the reddish area being bordered on each side with a darker 
band. The under surface is grayish to brownish. The head 
and cervical shield are yellowish brown, and there are two 
black spots on the vertex. 

In Canada the caterpillars become mature during the latter 
part of June and pupate in earthen cells from one to two inches 
below the surface of the ground. The pupa is reddish brown 



268 MANUAL OF VEGETABLE-GARDEN INSECTS 

and about f inch in length. The moths emerge during the 
latter part of July and August and have an expanse of If 
to If inches. The front wings vary from pale clay to dark 

reddish or blackish brown. 
The wing is crossed on the 
basal third by two wavy 
light lines. On the outer 
half are two prominent 
light spots, the inner one 
nearly round, the outer 
kidney-shaped. The hind 
wings are brownish gray, 
lighter in the center (Fig. 
158). 

Caterpillars hatching from eggs laid early in the season be- 
come partly grown before cold weather and hibernate in this 
condition ; some of the eggs laid late in the season do not 
hatch till the following spring. There is apparently but one 
generation a year. 

References 

Fletcher, Kept. CanafLa Ent. for 1904, pp. 223-225. 
Dept. Agr. Canada Ent. Bull. 10, pp. 1.5-16. 1915. 




Fig. 158. — The red-backed cutworm 
moth (X 1|). 



The Dark-Sided Cutworm 

ParagroHs messoria Harris 

This species is a native of North America, ranging from New 
Jersey westward to Colorado and California and northward. 
It is reported as very injurious in Ontario and Quebec. It is 
especially destructive to garden crops and has the habit of 
climbing young fruit-trees to feed on the opening buds. It is 
recorded as feeding on the following plants : cabbage, spinach, 
lettuce, potato, tomato, bean, peia, radish, turnip, beet, onion, to- 
bacco, sweet potato, corn, clover, buckwheat and grasses. It also 
attacks the opening buds of apple, currant, soft maple and grape. 



CUTWORMS AND ARMY-WORMS 



2C9 




So far as known, the dark-sided cutworm passes the winter 
in a partly grown condition. In the spring the caterpillars 
resume feeding and become mature in June and July. The full- 
grown caterpillar is slightly more than an inch in length. It is 
dull grayish in color with the sides of the body decidedly darker. 
Pupation takes place in the ground and the moths emerge in 
about a month. Sometimes the emergence is retarded, the 
pupal period extending over 
eight weeks. The pupa is 
about f inch in length, light 
yellowish brown marked 
with darker brown. 

The moth has an expanse 
of 1|- to If inches. The 
front wings are brownish 
gray with darker, s )me- 
times blackish markings 
consisting cf a double line 
extending halfway across 
the wing at the base, a double wavy line one third the distance 
from the base, a fainter single wavy line near the middle, an- 
other double wavy line about two thirds the distance from the 
base and just inside the outer margin there is an inconspicuous 
line of the ground color lying in a blackish shade. The or- 
bicular and reniform spots are both present, large and are out- 
lined with black. All the markings are distinct, including the 
median shade, but are not c;)ntrasted. The hind wing is dirty 
white shading to brown towards the margin (Fig. 159). The 
eggs of this species have not been described. There is but one 
generation annually. 

References 

Riley, 1st Rept. State Ent. Mo., pp. 74-76. 1869. 
Forbes, 23rd Rept. State Ent. 111., pp. 32-33. 1905. 
Dept. Agr. C-.nada Ent. Bull. 10, pp. 20-21. 1915. 



Fig. 159. 



- The dark-sided cutworm 
moth (X U). 



270 MANUAL OF VEGETABLE-GARDEN INSECTS 



The Striped Cutworm 

Paragpotis tessellata Harris 

The striped cutworm is particularly a vegetable pest attack- 
ing potato, tomato, sweet potato, radish, squash, cabbage, 
lettuce, celery, spinach, bean, cucumber, melon, beet, carrot, 
parsnip, onion and rhubarb. It is a serious enemy of alfalfa 
in Colorado and may also feed on flax, buckwheat, clover and 
corn. In Iowa it has been found injuring root-grafts of apple, 
pear, plum and cherry. This cutworm is restricted to the 

northern United States and 
Canada. 

The striped cutworm 
hibernates in a partly grown 
condition and becomes ma- 
ture in May and June. 
The full-grown larva is 
l^ inches in length, pale 
brownish tinged with yel- 
low above, grayish on the 
sides and greenish below. It has a median pale stripe 
bordered with brown ; a brownish subdorsal stripe, which 
is bounded below by a light line ; a narrow distinct 
white lateral stripe and a broad white stigmal band. Pupa- 
tion takes place in the soil, the pupal period occupying from 
two to three weeks. The moths are most abundant during 
July and August. The moth has an expanse of 1^ to 1^ inches. 
The front wings are grayish to blackish brown sometimes with 
a purplish tinge. The orbicular and reniform spots are distinct, 
and between these spots, and extending to the second cross 
line, is a contrasting dark brown or black area. There is a 
tuft of yellow hairs at the base of the front wing. The hind 
wings are brown becoming whitish towards the center and base 
(Fig. 160). There is but one generation a year. 




Fig, 



16C. — The striped cutworm moth 

(X U). 



CUTWORMS AND ARMY-WORMS 



271 



References 

Forbes, 23rd Rept. State Ent. 111., p. 34. 1905. 
Dept. Agr. Canada Ent. Bull. 10, pp. 29-30. 1915. 



The Dingy Cutworm 
Feltia subgothica Haworth, F. ducens Walker, and F. jaculifera Guenee 

Under the term dingy cutworm are included several forms, 
the moths of which have been given separate names by special- 
ists as indicated above. So far as known, the early stages 
and habits of these forms are practically identical. This cut- 
worm is widely distributed in the United. States and Canada, 
being more abundant in the northern part of its range. It is 
a general feeder, its food plants including corn, wheat, grasses, 
clover, strawberry, bean, pea, squash, cucumber, tomato, sweet 
potato, cabbage and horse-radish. It sometimes assumes the 
climbing habit and feeds 
on the buds of various 
fruit-trees. 

The dingy cutworm hi- 
bernates in a partly grown 
condition, completing its 
growth in the spring. 
When mature it is It 
inches in length, grayish 
brown, with a very wide 
buff-gray dorsal stripe out- 
lined by a narrow dark stripe on each side. Pupation 
takes place in the soil. The pupa is nearly I inch in length, 
honey-yellow, with dark brown markings. 

The moths are on the wing from early July to late Septem- 
ber, being most abundant in August. The adult has an expanse 
of It inches. The front wings are grayish brown marked with 
darker brown and suffused with purplish. The kidney-shaped 




Fig. 161. 



The dingy cutworm moth 

(X U). 



272 MANUAL OF VEGETABLE-GARDEN INSECTS 

spot is distinct and reddish brown ; the round spot is open in 

front and confluent with a broad marginal gray band. The 

hind wings are whitish, darker toward the margin or in some 

forms entirely brownish (Fig. IGl). The eggs are laid in 

August and September. The egg is about sV inch in diameter, 

dirty white wdth brown mottlings, dome-shaped and marked 

w^ith numerous ridges radiating from the apex. There is but 

one generation annually. 

References 

Cornell Agr. Exp. Sta. Bull. 104, pp. 574-579. 1895. 
Dept. Agr. Canada Ent. Bull. 10, pp. 26-27. 1915. 



The Shagreened Cutworm 

Feltia malefida Guenee 

In the southern states cabbage, potato, cotton and clover 
are sometimes attacked by a caterpillar which, from its 
roughened skin, has received the name of shagreened cut- 
worm. This cutworm does most of its work 
luiderground, living in a burrow into which 
it drags leaves and stems which it cuts off 
at night. The insect ranges from New 
York to New Mexico and California and 
southward to Argentina. The full-grown 
larva is nearly li inches in length, grayish 
brown in color with a very wide buff gray 
dorsal stripe. The head is pale brown with 
a curved, dark brow^n stripe on each side of 
the face. When mature, the caterpillar 
transforms within its burrow into a yellowish 
brown pupa about f inch in length. The 
pupal period in Texas varies from fifteen to twenty-seven 
days. The moth has an expanse of nearly 1| inches. The 
front wings are powdery pale gray with the front margin dark 




Fig. 162. — The 
shagreened cut- 
v/orm moth 

(X 1|). 



CUTWORMS AND ARMY-WORMS 



273 



gray. The reniform spot is conspicuous and dark gray. Just 
behind the so-calle<l round spot, which in this case is shaped 
like a tennis racket, there is a distinct short bhick bar. The 
hind wings are white, often lined with brown along the veins 
and with a narrow brown margin (Fig. 1()2). 

The seasonal history has not been carefully studied. The 
moths of the summer brood are abundant in Texas in late 
June and July. In New Jersey the moths are to be found in 
September. 

The Granulated Cutworm 

Feltia annexa Treitschke 

This species is most abundant in the tropics. It ranges 
through the West Indies, Mexico, Central America, southward 
to Chile and Argentina and northward to Nova Scotia and 
Minnesota, Among its food 
plants are tomato, cabbage, 
pea, bean, corn, wheat, 
grasses, clover, cotton and 
tobacco. 

In the northern part of 
its range the winter is 
passed in the larval state. 
The caterpillars reach ma- 
turity in May and June. 
The full-grown caterpillar is nearly li inches in length, 
dark gray, with a pair of yellowish drab oblique marks on each 
segment and a substigmatal pale gray line bordered with yellow- 
ish ; the underside of the body is pale greenish gray. Pupa- 
tion takes place in the ground. The reddish brown pupa is 
nearly f inch in length. The pupal period lasts from four to 
six weeks. In the North there are two generations annually. 
The first brood of moths is on the wing during June, July and 
August ; the second brood in August, September and October. 




Fig. 163. 



- The granulated cutworm 
moth (X ID- 



274 MANUAL OF VEGETABLE-GARDEN INSECTS 

The moth has an expanse of about li inches. In the female 
the front wings are dark grayisli brown with the outer border 
and a broad costal band clay-color. The orbicular and reni- 
form spots are small, distinct and connected by a black bar 
(Fig. 163). In the male the front wings are lighter and the 
hind wings are pearl-white with the front margin brownish. 
The eggs are white, about 3V inch in diameter and beautifully 
ribbed, one third of the ribs reaching the apex. The eggs hatch 
in about four days. 

References 

French, Can. Ent., 14, pp. 207-210. 1882. 
lU. Agr. Exp. Sta. Bull. 95, p. 362. 1904. 



The Clay-Backed Cutworm 

Feltia gladiaria Morrison 

The clay-backed cutworm is widely distributed in North 
America east of the Rockies. Its food plants include potato, 
tomato, sweet potato, bean, cabbage, onion, corn, clover, oats 
and grasses. This species, when abundant and lacking food, 

may adopt the army-worm 
habit. 

This cutworm hibernates 
in the larval condition 
and matures in early spring. 
The full-grown caterpillar 
is nearly li inches in 
length, dull greenish to 
dark brown with a broad 
median dorsal stripe vary- 
ing in color from straw-yellow to brown. This median 
stripe has given it the common name of clay-backed cut- 
worm. The larvse enter the ground in June and remain 
in the pupal condition for nearly six weeks. The moths 




Fig. 164. 



■ The clay-backed cutworm 
moth (X li). 



CUTWORMS AND ARMY-WORMS 275 

are on the wing during September and October. The moth 
has an expanse of about li inches. The front wings are 
grayish brown, the orbicular spot small, the reniform spot in- 
conspicuous. Through the middle of the wing there extends 
a pale narrow streak in which is a fine forked black line. In- 
side the subterminal line is a row of wedge-shaped black spots. 
The hind wings are brownish (Fig. 1G4). There is but a single 
generation a year. 

References 

Kv. Agr. Exp. Sta. Bull. .'")8, pp. 93-9.5. 1895. 
111. Agr. Exp. Sta. Bull. 95, pp. 358-359. 1904. 

The Black Army Cutworm 

Noctua fennica Tauscher 

Throughout the northern United States, Canada, northern 
Europe and Asia and in the Alpine regions the black army 
cutworm is found. It is more particularly a field crop pest, 
being especially fond of clo\'er and peas, and occasionally 
assumes the army-worm habit, doing serious injury to grass- 
lands and sometimes, when other food is not available, climbs 
trees, feeding on the foliage and even the bark. Asparagus, 
onions and other ^'egetables are occasionally attacked. 

The larvae hibernate in a half-grown condition and reach 
maturity quickly in the spring. The full-grown caterpillar is 
nearly If inches in length, beautifully striped with black and 
white. The caterpillars transform to light brown pupae in 
earthen cells in the ground and the moths emerge in about 
ten days. The adults are on the wing from late June to the 
last of August. The moth has an expanse of slightly more 
than li inches. The front wings are chocolate-brown; the 
spots are distinct, the reniform spot being reddish yellow and 
the round one gray. The hind wings are pale, brownish on 
the margin or entirely suffused with brownish. So far as 
known, there is but one generation a year. 



276 MANUAL OF VEGETABLE-GARDEN INSECTS 

References 

Lugger, 2nd Rept. State Ent. Minn., pp. 20-22. 1896. 
Dept. Agr. Canada Ent. Bull. 10, pp. 27-28. 1915. 

The Variegated Cutworm 

Peridroma margaritosa Haworth 

The variegated cutworm is nearly cosmopolitan in its dis- 
tribution, occurring in North and South America, the West 
Indies, Europe, northern Africa, southeastern Asia and Hawaii. 
In Europe it is of little economic importance but in the northern 
United States and Canada it is one of our most abundant and 
destructive cutworms. It is always present in greater or 
lesser numbers in this region and occasionally severe outbreaks 
occur when the caterpillars become so numerous that the food 
supply is exhausted and they assume the army-worm habit. 
The most striking instance of such an outbreak was in 1900 in 
the northwestern United States and British Columbia. This 
cutworm is a serious pest in greenhouses, where it gains entrance 
through the use of rotted sod containing the caterpillars. It 
has also the pernicious habit of climbing young trees and 
vines to feed on the buds, foliage and fruit. 

The variegated cutworm has the widest range of food plants 
of any of its class. It has been recorded as seriously injurious 
to the following vegetable crops : cabbage, turnip, radish, beet, 
carrot, lettuce, celery, rluibarb, asparagus, onion, squash, 
cucumber, potato, tomato, sweet potato, bean and pea. Among 
field crops it injures corn, w^heat, various grasses, clover, hops, 
sugar-cane and tobacco. Alfalfa is especially liable to attack 
in the western United States. Apple, cherry, pear, plum, prune, 
peach, currant, gooseberry, raspberry, blackberry, strawberry 
and grape are often severely injured. Of greenhouse and orna- 
mental plants, it is known to feed on \iolet, pansy, carnation, 
smilax, rose, sweet pea, hollyhock, sunflower, nasturtium and 
chrysanthemum. It has also been recorded as attacking 



CUTWORMS AND ARMY-WORMS 



277 



cedar, mulberry and box elder and such weeds as nettle, thistle, 
do^ fennel, fireweed and dock. 

In the northern part of its range this species hibernates 
either as pupse or as partly grown larvae. P'arther south hiber- 
nation occurs principally in the lar^'al stage. The over- 
wintered larvae emerge from hibernation in early spring and 
may cause serious damage before reaching maturity. The 
first brood of moths is on the wing in late May and early June, 
the second brood in late 
July, August and Septem- 
ber. Occasionally in the 
more southern localities 
there may be a partial 
third brood. 

The moth has an ex- 
panse of li to If inches. 
The front wings are brown- 
ish gray, washed toward 
the front margin with 
reddish in one form and with yellowish in the other. 
The round and kidney-shaped spots are distinct, the latter 
being the darker. The hind wings are pearly white with the 
veins and margin brown (Fig. 1G5). The females deposit their 
eggs in patches of sixty or more on the stems or leaves of low 
plants or on twigs or branches of trees. A single female may 
lay as many as 500 eggs. The egg is to' inch in diameter, 
dome-shaped, marked with about forty ribs radiating from the 
apex, cream colored when laid, changing to pinkish and becom- 
ing lilac just before hatching. 

The eggs hatch in five to six days and the young cater- 
pillars, after devouring the egg-shells, begin feeding on the 
leaves and buds. For the first week they may feed openly, 
crawling with a looping gait like a measuring-worm. Later 
they feed mostly at night and during the day remain hidden 




165. — The variegated cutworm 
moth (natural size). 



278 MANUAL OF VEGETABLE-GARDEN INSECTS 

in the earth or under boards or rubbish. The caterpillar 
becomes mature in twenty-five or thirty days and is then 
from li to 2 inches in length. The general color is ashen or 
light dirty brown lightly mottled with darker brown. The 
underside is light gray. This cutworm may be distinguished 
from all other common species by the presence of from four to 
six yellow spots along the mid-dorsal line. Pupation takes 
place within an earthen cell just below the surface of the 
ground. The pupa is reddish brown and about to inch in 
length. In summer the insect remains in the pupal stage 
from two to three weeks. Under greenhouse conditions the 
complete life cycle requires forty-five to fifty-four days. 

References 

Lintner, 5th Rept. State Ent. N. Y., pp. 200-206. 1889. 

Cornell Agr. Exp. Sta. Bull. 104, pp. 579-584. 1895. 

Fletcher, Rept. Canada Ent. for 1900, pp. 215-227. 

Wash. Agr. Exp. Sta. Bull. 47. 1901. 

U. S. Div. Ent. Bull. 29, pp. 46-64. 1901. 

Davis, 27th Rept. State Ent. 111., pp. 84-88. 1912. 

State Ent. Nebr. Bull. 1, pp. 35-41. 1913. 

Canada Dept. Agr. Ent. Bull. 10, pp. 17-20. 1915. 

The White Cutworm 

Paragrotis scandens Riley 

From its habit of climbing fruit-trees and destroying the 
opening buds, the white cutworm has become notorious. 

In a severe outbreak in 
western New York in 1893 
/ ^ . and 1894, over 90 per cent 

j of the caterpillars found on 
C,^^- fruit-trees were of this 

Fig. 166. — a full-grown white c-utworm species. It is a native in- 
(naturai size). ^^^^ generally distributed 

over the northern United States and Canada east of the Rocky 
Mountains. In addition to injuring fruit-trees and grape vines. 




CUTWORMS AND ARMY-WORMS 



279 



it lias })een recorded as attacking radish and cabbage though 
doubtless it feeds on other garden vegetables. 

The partly grown caterpillars hibernate. They emerge in 
early spring and soon complete their growth, usually in the 
latter part of May and June. The mature caterpillar is If 
inches in length, of a very light yellowish gray with irregular 
whitish areas on the dorsal 
and lateral aspects of the 
body. There is a faint 
white stripe just below the 
spiracles (Fig. 166). Pupa- 
ti[)n takes place in the 
ground and the moths 
emerge during June and 
July. The pupa is f 
inch in length. The moth 
has an expanse of If inches. The front wings are ash- 
gray suffused with either brownish, yellowish or reddish. There 
is a dark area at the posterior half of the reniform spot. The 
hind wings are whitish with a double dusky shade on the outer 
edge and have a dark discal spot (Fig. 167). The eggs of this 
species have not been described. There is only a single genera- 
tion a year. 

References 

Riley, 1st Rept. State Ent. Mo., pp. 76-79. 1869. 
Cornell Agr. Exp. Sta. Bull. 104, pp. 567-569. 1895. 
Dept. Agr. Canada Ent. Bull. 10, pp. 21-22. 1915. 




Fig. 167. — The white cutworm moth 
(natural size). 



The Glassy Cutworm 

Hadena devastatrix Brace 

This cutworm is more distinctly a forage crop pest but 
occasionally becomes injurious to vegetables. It is widely 
distributed throughout the United States and Canada, more 
abundantly in the North. It feeds on corn, grasses, wheat, 



280 MANUAL OF VEGETABLE-GARDEN INSECTS 



oats, barley and strawberry. In mixed fields of timothy and 
clover, it is recorded that the former was destroyed while the 
clover remained uninjm-ed. Beans, lettuce and cabbage are 
sometimes attacked. Unlike the more common cutworms, 
this species rarely comes to the surface, but works in a burrow, 
feeding on the roots and stems below ground. There is a case 
on record in Ohio of peach seedlings being destroyed in this way. 
Hibernation takes place as partly grown larvse. Some of 
them become mature in early May but the greater number 

during June and July. The 
full-grown caterpillar is \^ 
inches in length, dirty white 
with a greenish tinge and 
has a translucent glassy 
appearance ; the head is 
reddish brown. Pupation 
takes place in earthen cells. 
If inches in length by f 
inch in width. These cells 
are formed a few inches 
below the surface of the 
ground. The pupa is nearly an inch in length and of a 
reddish brown color. 

The moth has an expanse of 1^ to If inches. The front 
wings are pale ashy gray to dark brownish gray, mottled with 
darker brown. The subterminal transverse line is whitish and 
usually distinct. On the inner margin of this line is a row of 
five or six wedge-shaped black spots. The hind wings are 
brownish, darker on the outer third (Fig. 168). There is ap- 
parently but a single brood annually, the eggs being laid in the 
latter part of the season, the greater number after August first. 

References 

Forbes, 23rd Kept. State Ent. 111., pp. 19-20. 1905. 
Dept. Agr. Canada Ent. Bull. 10, pp. 24-25. 1915. 




Fig. 168. — The glassy cutworm moth 
(X H). 



CUTWORMS AND ARMY-WORMS 



281 



The Yellow-Headed Cutworm 

Hadena nrctica Boisduval 

Like the glassy cutworm, this species hves from one to two 
inches below the surface of the ground, feeding on the roots 
and cutting off the underground stems of plants. The moths 
are attracted to lights in great numbers and are often seen ; 
the caterpillars, however, have not elicited as much attention 
by their injuries as would be expected. It is primarily a field 
crop pest injuring grasses, oats, wheat and corn. It also feeds 
on cabbage, spinach, turnip, lettuce and the succulent shoots 
of roses and currants. The insect is widely distributed through- 
out the northern United States and Canada. 

The winter is passed as partly grown caterpillars. The 
larviie are most destructive in May and June. The full-grown 
caterpillar is 1^ inches in 
length and closely resembles 
the glassy cutworm, from 
which it may be distin- 
guished by its yellow head. 
Pupation takes place in the 
ground. The pupa in size 
and color is almost identical 
to that of the glassy cut- 
worm. The adults emerge 
in about a month and are on 
the wing from June to September. The moth has an expanse of 
nearly 2 inches. The front wings are rich reddish brown, 
bluish gray at the base and with a broad transverse band of 
the same color near the outer margin. The whole wing is mot- 
tled with varying shades of deep brown and blue-gray, giving 
it the appearance of a rich brocade. The hind wings are 
brownish, darker on the outer third and with a dark discal 
spot. The thorax is ornamented with dense tufts of chestnut- 




FiG. 1G9. 



— The yellow-headed cutworm 
moth (natural size). 



282 MANUAL OF VEGETABLE-GARDEN INSECTS 




colored hairs (Fig. 109). The eggs of this species have not 
been described. There is only one brood annually. 

References 

Forbes, 2.3rd Ropt. State Ent. 111., p. 21. 1905. 
Dept. Agr. Canada Ent. Bull. 10, pp. 25-26. 1915. 

The Spotted-Legged Cutworm 

Porosagrotis vetusta Walker 

Although a rather uncommon species, this cutworm has 

occasionally appeared in destructive numbers in Virginia and 

North Carolina. It ranges 
from Nova Scotia south to 
Georgia and west to Colo- 
rado. Its food plants in- 
clude cowpea, watermelon, 
cantaloupe, kale, spinach, 
lettuce, cabbage, cultivated 

dandelion, parsley and corn. It has also been recorded as 

climbing peach-trees to feed on the buds. 

In New York the winter is probably passed as partly grown 

caterpillars which complete 

their growth the following 

season and pupate in July. 

The moths are on the 

wing in late July, August 

and September. In the 

South the caterpillars are 

destructive in April and 

May and again in Sep- 
tember. The full-grown 

caterpillar is about li inches in length; the whole body 

above the spiracles is a dull, dark grayish brown ; the 

underside is lighter (Fig. 170). The body is marked with 



Fig. 170. — A full-grown spotted- 
legged cutworm (X U)- 




Fig. 171. 



The spotted-legged cutworm 
moth (X ID- 



CUTWORMS AND ARMY-WORMS 



283 



numerous black piliferous tubercles. The base of the true 
le^s behind and the prolegs in front bear each a greenish black 
spot, whence the common name. The moth has an expanse 
of about li inches and is easily distinguished from the other 
species here treated. The front wings are pale powdery ash- 
gray, sometimes tinged with pinkish. There is a small dark 
median spot and inside the submarginal line is a row of small 
triangular black spots. The hind wings are white (Fig. 171). 
The egg has not been described. The pupa is about f inch 
in length and pale brown in color.- 

References 

Corni'll Agr. Exp. Sta. Bull. 104, pp. 570-571. 1895. 
U. S. Bur. Ent. Bull. 109, pp. 47-51. 1912. 



The Speckled Cutworm 

Mameslra subjuncta Grote and Robinson 

The speckled cutworm ranges throughout Canada and the 
northern United States southward to Colorado and New 
]\Iexico. So far it has been recorded as feeding only on cab- 
bage and climbing fruit- 
trees to devour the buds 
and foliage. 

It is not known in what 
stage hibernation takes 
place, though it is probably 
as partly grown caterpillars. 
The mature caterpillar is 
slightly over 1| inches in 
length, reddish gray, mi- 
nutely speckled with black and white, hence the common name. 
When they have completed their growth, the larva? burrow 
into the ground and transform to dark brown pupie from which 
the moths emerge from late June to September. The moth 




Fig. 172. — The speckled cutworm moth 
(X U). 



284 MANUAL OF VEGETABLE-GARDEN INSECTS 

has an expanse of about li inches. The front wings are dull 
gray with the usual pattern lightly marked but distinct. There 
is a dark dash at the base of the wing and another below the 
middle. The subterminal line has two long teeth running 
to the margin. The hind wings are dirty white, darker towards 
the margin (Fig. 172). 

Reference 

Riley, 1st Rept. State Ent. Mo., pp. 84-85. 1869. 



The Clover Cutworm 

Mamestra trifolii von Rottenburg 

This cutworm ranges throughout the northern hemisphere 
and has been reported from Chile. It has been especially in- 
jurious to cabbage in the vicinity of Washington, D. C, and in 
Canada it has proved destructive to peas and clover. It also 
attacks mangel, turnip, beet, lettuce and spinach. Among its 

wild food plants are lamb's 
quarters and purslane. 

Unlike many cutworms, 
it passes the winter in the 
pupal stage. The spring 
brood of moths is on the 
wing in May and June and 
the second brood in August 
and September. The first 
brood of caterpillars is rel- 
atively small and does com- 
paratively less injury. The second brood in August and Sep- 
tember often proves very, destructive to peas, clover and late 
cabbage. The mature caterpillar is about 2 inches in length, 
greenish yellow, mottled with brown and black, and has a broad 
pinkish band below the spiracles. Pupation takes place in 
the ground. 




Fig. 173. — The clover cutworm moth 

(X U). 



CUTWORMS AND ARMY-WORMS 



285 



The moth has an expanse of li to 1^ inches. The front wings 
are yellowish brown marked with gray and dark brown. The 
posterior, half of the reniform spot is fuscous (Fig. 173). Ap- 
parently the eggs of this species have not been described. 

Reference 
Dept. Agr. Canada Eut. Bull. 10, p. 26. 1915. 



The Bristly CrTWOK:\i 
Mamestra renigera Stephens 

The range of the bristly cutworm is from Georgia and New 
]\Iexic() northward to Colorado, Ontario and Nova Scotia. It 
is mainly a grass and garden pest, feeding on clover, grasses, 
turnip, corn, cabbage, chic- 
ory, comfrey and garden 
flowers. It feeds chiefly 
on the roots. 

The winter is passed as 
partly grown larvfe, which 
cause the most serious in- 
jury in April and May. The 
full-grown caterpillar is 
about an inch in length, 
yellowish gray marked with 
two distinct black lateral stripes. Scattered over the entire 
body are many black and yellow bristles — hence its common 
name. Pupation takes place in the ground. The moth has 
an expanse of about an inch. The front wings are rich brown, 
the reniform spot green margined with white and the orbicular 
spot inconspicuous. There are on each wing a distinct quadrate 
green patch on tlie hind angle and an elongate one near the 
middle of the base. The hind wings are smoky, darker towards 
the edge (Fig. 174). There are two generations annually. The 




Fig. 174. 



The bristly cutworm moth 
(X 1|). 



286 MANUAL OF VEGETABLE-GARDEN -INSECTS 

moths of the first brood are on the wing from late May to the 
middle of July ; those of the second, from August to October. 

Reference 
Forbes, 23rd Rept. State Eiit. 111., pp. 35-36. 1905. 



The Bronzed Cutworm 

Nephelodes minians Guenee 

Although rarely injurious in vegetable-gardens, the bronzed 
cutworm is often destructive to corn, grain and grasses. This 
species ranges throughout the northern United States and 
Canada. 

The winter is passed as partly grown caterpillars. They 
mature in June and are then nearly 2 inches in length, of a 

grayish brown or bronze 
color with conspicuous pale 
stripes extending the whole 
length of the body, a median 
stripe, and on each side two 
stripes above the spiracles, 
the vipper one broader and 
more distinct. The dorsal 
stripes cross the cervical and 
anal shields. The cater- 
pillars transform to dark 
brown pupse in earthen cells. The pupal period may last as 
long as ten weeks. The moth has an expanse of about 1^ 
inches. The front wings are rich reddish brown often suffused 
with violet, and crossed near the middle by irregular darker 
brown bands. The hind wings are brown suffused with reddish 
or violet (Fig. 175). The eggs of this species have not been 
described. Sp far as known, there is only a single generation 
annually. 




Fiu. 175. — The bronzed cutworm moth 
(X II). 



CUTWORMS AND ARMY-WORMS 287 



References 



Lintner, 1st Rept. State Ent. N. Y., pp. 91>-11(). 1882. 
Forbes, 23rd Rept. State Ent. 111., pp. 29-31. 1905. 
Dept. Agr. Canada Ent. Bull. 10, pp. 28-29. 1915. 



The Army Cutworm 

Chorizagrotis auxiliaris Grote, C. introferens Grote, C. agrestis Grote 

This is one of the most common and injurious species In 
Colorado, Montana, California and Alberta. It is generally 
distributed throughout western North America from Mexico 
northward and as far east as Louisiana, Kansas and Manitoba, 
It is distinctly a surface feeder, burrowing very little. When 
abundant this species assumes the army-worm habit to a 
marked degree ; in California it is known as the western army- 
worm. Its food plants are cabbage, horse-radish, mustard, 
turnip, beet, corn, pea, celery, tomato, potato, onion, rhubarb, 
alfalfa, lupine, clover, timothy and other grasses, wheat, oats, 
barley, rye and strawberry. The caterpillars also climb and 
feed on the buds of fruit- and forest-trees. 

The winter is passed as partly grown larvae on or in the 
ground. In INIontana they beconie mature in early April. 
The full-grown caterpillar is 1^ to 2 inches in length, dull green 
to greenish brown with the back broadly pale or with two broad, 
lighter dorsal stripes. The underside is lighter, nearly white 
at the level of the spiracles. The dark side is divided by a 
fine pale line and the light dorsum strongly shaded with white ; 
the head is light yellow mottled with brown but without brown 
stripes on the sides. Occasionally the larva is almost uniform 
dark green above except for two rows of pale patches on the 
back. Pupation takes place in earthen cells in the ground 
two or three inches from the surface. The dark brown pupa 
is about f inch in length. The moths emerge in about two 
months or from the last of June to the middle of July. The 



288 MANUAL OF VEGETABLE-GARDEN INSECTS 



moth has an expanse of nearly If inches. The front wings 
are gray or clay-colored shaded with brown and marked with 
black. The orbicular and reniform spots are distinct, outlined 
with dirty white and the basal two thirds of the front margin 
of the wing has a broad light band. The hind wings are brown- 
ish, darker towards the margin (Fig. 176). In the agrestis form 
the markings are nearly all obscure. Although the moths 

emerge in late June and 
early July, they do not 
deposit their eggs until 
September and October. 
The yellowish white, globu- 
lar, slightly flattened eggs, 
about 4^0 "^ch in diameter, 
are deposited on the surface 
of the soil often in newly 
plowed fields and hatch in 
nine or ten days. The 
larvae become partly grown before the advent of cold weather. 
There is onlv one generation a vear in Montana and Alberta. 




Fig. 176. 



The army cutworm moth 
(X lA). 



References 

Mont. Agr. Exp. Sta. Bull. 17, pp. 10-18. 1898. 
Mont. Agr. Exp. Sta. Circ. 4. 1910. 
Col. Agr. Exp. Sta. Bull. 98, pp. 17-22. 190r). 
Coolev, Jour. Agr. Research, (i, pp. 871-881. 1916. 
Dept. Agr. Canada Ent. Bull. 13. 1916. 



The Army-Worm 

Heliophila {Leucania) imipuncta Haworth 

The army-worm is one of the most cosmopolitan of insects. 
It occurs in practically every region of the world except Africa 
but is most injurious in the northern United States and Canada. 
In this species the habit of migrating from field to field in large 
numbers, or so-called armies, is developed to a high degree and 



CUTWORMS AND ARMY-WORMS 289 

has attracted widespread popular interest. In North America 
periodic outbreaks have been recorded at intervals since 174:]. 
One of the most widespread and injurious broke out in 18(51 
when the caterpillars appeared in greater or less abundance 
in twenty states. Other notable outbreaks occurred in 1896 
and in 1914. The insect is always present in low pastures and 
meadows and nearly every year there are local outbreaks in 
some parts of the country. Many theories have been offered 
to account for these widespread and periodic manifestations 
but no satisfactory explanation has been advanced. Whatever 
factors are concerned in determining the abundance of this 
insect in any one year, they must be effective over a wide area. 
The abundance of the species in different years is undoubtedly 
dependent on a combination of circumstances, such as temper- 
ature, drought and moisture, and the prevalence of fungous 
diseases and parasitic insect enemies. 

The army-worm feeds normally on grasses. When abun- 
dant it completely destroys its food supply in a given area and 
then migrates in armies, devouring almost every green thing 
in its path, although it eats clover only sparingly. Besides 
grains and grasses, it feeds on bean, sugar-beet, sweet potato, 
parsley, cucumber, watermelon, celery, pepper, strawberry, 
cranberry, sugar-cane and many weeds. The caterpillars 
feed at night or during cloudy weather ; in the heat of the day 
they hide under any convenient shade. 

In the North hibernation takes place as partly grown cater- 
pillars, in the South in the larval and adult stages and excep- 
tionally in the egg stage. The over-wintering caterpillars are 
rarely sufficiently abundant to attract much notice. In New 
York these mature in May ; in New Jersey in April. The 
caterpillar (Fig. 177) is described by Slingerland as follows : 

When full-grown, army-worms measure nearly 1^ inches 
in length. They are of a general greenish black color, much 
lighter on the venter, which is more or less mottled with blackish, 



290 MANUAL OF VEGETABLE-GARDEN INSECTS 



and each side bears several distinct stripes. Along each side 
of the body extenfl three stripes of about the same width ; the 
one just below the spiracles is of a light greenish yellow with 
whitish edges ; the one bordering on the dorsum is a little darker 
with a mottled greenish black center and narrow white lines 

along its edges ; the 
central stripe, or the 
one with the spir- 
acles in its lower 
edge, is black, some- 
times lighter along 
its center. The 
dorsum is finely 
mottled with green- 
ish black and closely 
resembles the dark 
stigmatal stripe in 
color ; along the 
middle line of the 
dorsum there ex- 
tends a narrow white stripe, usually quite indistinct except 
on the thoracic and anal segments. The six true legs 
are light brown in color, and each proleg is marked with 
a large, shiny, blackish spot. The head is of a greenish 
brown color, rather coarsely mottled w ith black which merges 
into distinct blackish stripes along the sutures. There is con- 
siderable variation in general color among the caterpillars, 
some being much lighter than others, due to differences in the 
intensity of the stripes and the mottlings on the body. 

The moths deposit their eggs in the sheath or unfolded base 
of the leaves of grains and grasses. The eggs are laid in rows 
of ten to sixty and covered with a white, gelatinous substance 
which fastens them together and folds the edge of the leaf 
closely around them. Each female moth lays from 500 to 




Fig. 177. — Army-worms, showing variation in color 
(slightly enlarged). 



CUTWORMS AND ARMY-WORMS 



291 



750 eggs. The egg is about to inch in diameter, spherical, 
nearly smooth and very light yellow in color. The eggs hatch 
in six to ten days. The young caterpillar is translucent whitish, 
with a dark brown head and is about iV inch in length. In 
the course of its development the larva passes through six 
immature stages, molting five times. In the first two stages 
the first two pairs of prolegs are not fully developed and the 
young larvae consequently loop along like measuring-worms. 
When disturbed they drop by means of a silken thread. In the 
third stage they begin to acquire the characteristic stripes 
of the mature caterpillar. From twenty to thirty days are 
usually spent in the larval stage. When full-grown the cater- 
pillars enter the ground, where at a short distance below the 
surface they transform to mahogany brown pupse about f 
inch in length. In about three weeks the moths emerge (Fig. 
178). They have an ex- 
panse of about If inches. 
The front wings are brown 
and are marked with two 
more or less distinct 
lighter spots near the 
middle. In the reniform 
spot there is a small, 
distinct white dot. The 
hind wings are dull gray, 
paler at the base. 

In New York there are usually three broods of caterpillars 
annually ; the first brood or over-wintered larvse in xA.pril and 
May, the second in July and the third in September, the last 
not maturing until the following spring. There are thus only 
two generations a year in this state. In the South there are as 
many as five or six generations annually. In the North the 
second brood is the most injurious but in the South either the 
first, second or third may prove the most destructive. 




Fig. 178. — The army-worm moth 
(natural size). 



292 MANUAL OF VEGETABLE-GARDEN INSECTS 



References 

Third Kept. U. R. Ent. Comm., pp. 89-156. 1883. Bibliography. 

N. H. Agr. Exp. Sta. Bull. 39. 1896. 

Cornell Univ. Agr. Exp. Sta. Bull. 133. 1897. 

Ky. Agr. Exp. Sta. Bull. 137. 1908. 

Neb. State Ent. Bull. 1, pp. 41-48. 1913. 

Cornell Univ. Agr. Exp. Sta. Bull. 376. 1916. 

Davis and Satterthwait, Jour. Agr. Research, 6, pp. 799-812. 1916. 



The Fall Army- Worm 

Laphygma frugiperda Smith and Abbot 

The range of the fall army-worm extends from Canada 
southward through Central America and the West Indies to 
Argentina, it being most injurious in the warmer parts of its 
range. It is called the fall army-worm because in the United 
States it usually appears in armies later in tlje season than the 
true army-worm. Destructive outbreaks have been recorded 
from Nebraska to Indiana and southward in the Mississippi 
Valley and in the Gulf states to Georgia. Along the Atlantic 
Coast outbreaks of lesser importance have been reported as 
far north as Connecticut. Its favorite food plants are certain 
grasses and in the South it is known as the grass-worm. When 
abundant and migrating it becomes a general feeder. Serious 
injury to the following crops has been reported : rice, teosinte, 
kaffir corn, millet, cowpea, chick-pea, velvet bean, clover, 
corn, alfalfa, oats, rye, barley, cotton, tobacco, strawberry, 
sweet potato, spinach, cabbage, tomato, potato, cucumber 
and turnip. It also occasionally climbs trees and has been 
recorded as injuring orange, peach and apple. 

Normally hibernation takes place in the pupal stage, at least 
in the northern part of its range. It is quite probable, however, 
that in the South the larvae and moths may also hibernate. In 
southern Nebraska the moths emerge in late May and June. 
They have an expanse of li inches. The front wings are dull 



CUTWORMS AND ARMY-WORMS 



293 



grayish brown with the orbicular spot oblique ; in one form 
all markings are indistinct ; in the other there is near the tip 
of the wing a bluish white spot and the orbicular spot is crossed 
by a diagonal white bar ; the cross lines are also more distinct. 
The hind wings are pearly white margined with brownish 
(Fig. 179). The moth deposits its eggs in clusters of fifty to 
one hundred or more on the leaves of its food plants. They 
are arranged in two layers, one above the other, and covered 
with fine gray down from the moth's body. The egg is nearly 
spherical, white to pinkish, about wo^ inch in diameter and 
marked with about sixty 
vertical ribs, crossed with 
smaller ones. The eggs 
hatch in ten days or less 
and the caterpillars reach 
maturity in about a month. 
The full-grown caterpillar 
is li inches in length, 
varying in color from 
pale yellowish brown to 
blackish and is marked with three narrow^ pale yellow stripes 
on the back and a broader yellowish line on each side. The 
larvae transform to dark brown pupie, about i inch in length, 
in earthen cells slightly below the surface of the ground. The 
pupal cells are placed vertically and the pupse lie with their 
heads directed upward. The cells in which hibernation takes 
place are heavily lined with silk. 

Recent observations have shown that in southern Nebraska 
there are three generations a year. The spring brood of moths 
appears in May and June. The caterpillars of this brood 
occur in July and give rise to a second brood of moths in late 
July and early August. The caterpillars of the second brood 
mature in August and early September. The third brood of 
moths appears in September and eggs are deposited within a 




179. — The fall army-worm niDtli 
(X \h). 



294 MANUAL OF VEGETABLE-GARDEN INSECTS 

short time. The last or fall brood of caterpillars does the 
greatest damage during September and October. In the South 
another generation probably occurs but definite information 
in regard to this point is not available. 

References 

U. S. Div. Ent. Bull. 29, pp. 13-45. 1901. Bibliography. 
Neb. State Ent. Bull. 1, pp. 48-57. 1913. 

The Beet Army- Worm 

Caradrina exigua Hiibner, C. fiavimaculata Harvey 

This cosmopolitan army-worm is represented in North 
America by a variety (C. flavimacidata) which, by some author- 
ities, is considered as a distinct species. In North America 
it is found only in the western United States and Mexico. Its 
favorite food plant is the sugar-beet but it also feeds on corn, 
alfalfa, potato, pea, onion, cotton and many weeds. In Egypt 
and the Sudan it is very destructive to cotton and lucerne, 
while in India it does serious injury to the indigo plant. 

The hibernation habits are not known with certainty. In 
Colorado it would appear from the late emergence of the moths 
in the fall that the winter is passed in the adult state. In 
California the first brood moths appear in April ; in Colorado 
in May. The moth has an expanse of about an inch. The 
front wings are grayish brown ; the small, round, orbicular 
and reniform spots are pale. The hind wings are opalescent 
white with the veins and margin brown (Fig. 180). The eggs 
are deposited in masses of twelve to fifty on the underside of 
the leaves and covered with grayish down. The egg is pyram- 
idal in shape, the upper third in the form of a cap and sep- 
arated from the remainder by a white band. The eggs hatch 
in about four days. The young larvje live in small colonies 
and skeletonize the leaves under the protection of a web spun 



CUTWORMS AND ARMY-WORMS 



295 



over their feeding ground. When half grown they abandon 
their webs and feed openly, de\'oiiring the whole leaf except 
the larger veins. They feed only at night, during the day 
remaining hidden in the soil. In about two weeks the cater- 
pillars become full-grown and are then slightly over an inch 
in length. They vary considerably in color but are usually 
green with a broad, gray 
or black lateral band bor- 
dered on the upper side by 
a narrow white line. The 
mature caterpillars burrow 
a short distance into the 
soil and there in earthen 
cells transform to yellowish 
brown pupre a little less 
than i inch in length. 
The insect remains in this condition for about two 
weeks. In California there are two or three broods a season, 
the second being the most injurious. 




P'iG. ISO. — The l)eet army-worm moth 
(X If). 



References 

U. S. Div. Ent. Bull. 33, pp. 37-46. 1902. 
Col. Agr. Exp. Sta. Bull. 98, pp. 13-15. 1905. 

King, 3rd Rept. Wellcome Res. Lab. Gordon Mem. College, Khartouin, 
pp. 234-235. 1908. 



The Yellow-Striped Army-Worm 

Prodenia ornilhogalli Guenee 

This species ranges throughout the United States from 
Massachusetts to California and southward to Costa Rica and 
the West Indies. It is more injurious in the southern part 
of its range, where it attacks cotton and tobacco. It also feeds 
on beet, cabbage, potato, tomato, salsify, asparagus, water- 



296 MANUAL OF VEGETABLE-GARDEN INSECTS 



melon, cucumber, corn, wheat, alfalfa and clover. As a 
climber it attacks peach, raspberry and grape. It is reported 
as also feeding on cotton bolls and the heart of young corn 
plants in the same way as the cotton boll-worm. 

Hibernation takes place either as larvae, pupae or adults. In 
California the spring brood of caterpillars is most abundant in 

May and June. The full- 
grown larva is from 1^ to 
2 inches in length (Fig. 181). 
There are two varieties ; one 
is velvety black above and 
reddish brown beneath with 
bright yellow lines on the 
and has the back marked 




Fig. 181. — The yellow-striped army- 
worm (natural size). 



two prominent and many fine 
side ; the other is reddish gray 
with a pair of triangular black spots on each segment, the 
lateral markings not being so distinct. In late May and 
June the caterpillars transform in earthen cells to rich reddish 
brown pupae and the moths emerge two or three weeks later. 
The moth has an average 
expanse of li inches. The 
front wings are brownish 
gray with a beautiful and 
complicated pattern. The 
reniform spot is small and 
pyriform ; the orbicular is 
elongate oval, and is placed 
in a light-colored bar ex- 
tending towards the hind 
angle of the wing. In the middle of the wing there is a 
small sharply defined white \. The hind wing is opalescent 
white, narrowly margined with brown (Fig. 182). Nothing is 
known as to the egg-laying habits of this species. In Cali- 
fornia it is said to be double brooded, the spring brood being 
the more destructive. 




Fig. 



182. — The yellow-striped army- 
worm moth (X 1 J) . 



CUTWORMS AND ARMY-WORMS 297 



References 



111. Agr. Exp. Sta. Bull. GO, pp. 496-497. 1900. 

Essig, Insects of California (Ed. 2), pp. 401-402. 1915. 



The Semi-Tropical Army-Worm 

Prodenia cridania Cramer 

The semi-tropical army-worm ranges from Georgia, Florida 
and Texas southward through Central America and the West 
Indies to Argentina. In Florida it has been reported as in- 
jurious to tomato, potato, sweet potato, eggplant, pepper, 
okra, collard and cowpea. The caterpillars commonly climb 
the plants on which they feed and when abundant may assume 
the army-worm habit. 

In this species breeding is almost continuous throughout 
the year, there being four or more generations annually. The 
moth has an expanse of about \\ inches. The front wings are 
dull gray, sprinkled and dotted with brownish and black. The 
hind wings are pearly white. The eggs are laid in irregular 
masses, sometimes in two layers, and are covered with whitish 
down from the female's body. The egg is about tV inch in 
diameter, hemispherical, finely ribbed and pale green in color. 
The eggs hatch in about six days and the caterpillars mature 
within three weeks. The full-grown larva is 1 to li inches 
in length and varies in color from dark grayish to nearly black. 
It is marked with a median, subdorsal and lateral yellow 
stripes. The mahogany brown pupa, about f inch in length, 
is to be found in the ground a few inches from the surface. 
The insect passes about ten days in this stage. 

Reference 
U. S. Bur. Ent. Bull. 66, pp. 53-70. 1909. 



298 MANUAL OF VEGETABLE-GARDEN INSECTS 

Other Cutworms 

Paragrotis atomaris Smith 

This cutworm is abundant in California where it is reported 
as feeding on weeds and garden crops. It also climbs grape 
vines and prune trees to feed on the buds and foliage. The 
full-grown caterpillar is 1^ inches in length and light gray in 
color. This species is said to hibernate in both the larval and 
pupal stages. The almost uniform gray moths emerge in April. 

The following species have been recorded as occasionally 
injurious : 

Dargida procindus Grote. In British Columbia. 
Feltia venerahilis Walker. In Manitoba. 
Leucania albilinea Hiibner. In the eastern United States. 
Paragrotis detersa Walker. In Manitoba. 
Paragrotis insnlsa Walker. In Manitoba. 
Paragrotis perexceUens Grote. In British Columbia. 
Porosagrotis orthogonia Morrison. In Alberta. Injurious 
to grain. 

Rhynchagrotis alternata Grote. In Missouri. 
Rhynchagrotis placida Grote. In Michigan. 

The Control of Cutworms and Army-Worms 

The means employed for the control of cutworms will vary 
according to the crop, the conditions under which it is grown 
and the habits of the species causing the injury. 

In small vegetable-gardens and greenhouses, hand-picking 
may be used to advantage. Careful watch of the plants should 
be kept and whenever injury is noticed, the soil around the base 
of the plants should be searched and the cutworms destroyed. 
Shingles or small boards laid about the beds will form attrac- 
tive hiding places for the worms during the day ; here they may 
.be easily found and destroyed. When such plants as tomatoes 



CUTWORMS AND ARMY-WORMS 299 

are transplanted, they may be protected by using cardboard 
or tin cylinders sunk a short distance in the soil. Tin cans 
with the top and bottom removed are convenient for this 
purpose. Greenhouses often become infested by cutworms 
in the rotted sod used in the beds. This may be prevented 
by sterilizing the soil by steam before using. 

Probably the most practical, cheap and convenient method 
of cutworm control is the use of poisoned baits. These may 
be employed equally as well in the home garden, greenhouse 
or in the field. For general field work, a bait made according 
to the following formula has been found effective against the 
variegated cutworm and others of similar habits : 

Bran 20 pounds 

Paris green 1 pound 

Molasses 2 quarts 

Oranges or lemons 3 fruits 

Water 3i gallons (about) 

The dry bran and paris green are thoroughly mixed in a tub 
or similar receptacle. The juice of the oranges or lemons is 
squeezed into the water; the remaining pulp and peel are 
chopped into fine bits and added to the water. The molasses is 
dissolved in the water and the bran and poison wet with it, 
the mixture being constantly stirred so as to dampen the mash 
thoroughly. Only enough water should be used to just moisten 
the mash but not enough to make it sloppy. 

This quantity of bait will treat about three acres. The 
material should be scattered broadcast evenly over the in- 
fested area at nightfall. If applied during the day, it dries 
out and is not then attractive to the cutworms. In the garden 
or greenhouse a small quantity of the bait may be placed near 
each plant. 

Another formula which has given excellent results in western 
Canada is as follows : 



300 MANUAL OF VEGETABLE-GARDEN INSECTS 

Shorts 50 pounds 

Paris green 1 pound 

Molasses 2 quarts 

Water 2^ gallons 



worms. 

case, 

should 



The ingredients should be mixed as in the preceding formula 
and applied in the same way. This is said to give better 

results under dry 
conditions. 

These baits are 

also effective in the 

control of army- 

In such 

the baits 

be sown 

liberally in the path 

of their march. 

A bait may be 
made of bundles of 
fresh clover, grass or 
other tender vegeta- 
tion dipped in of 
sprinkled with a mix- 
ture of paris green 
and water. Small 
piles of this material 
are then distributed 
the evening at 




Fig. 183. — A tunc^w with post-holes in the l)ottoni, 
along the edge of a corn field to stop an army-worm 
invasion. 



m 



short distances in 

the infested fields. 

Much may be done to prevent injury from cutworms by 

fall plowing of land intended for vegetable crops. In this way 

hibernating shelter is reduced to a minimum and many of the 

caterpillars are either killed or exposed to the attacks of their 



CUTWORMS AND ARMY-WORMS 301 

enemies. Clean farming througli the destruction of weeds 
along fences and ditch banks will also do much to prevent the 
prevalence of cutworms. 

Whenever cutworms assume the army-worm habit, their 
achance may be stopped by plowing a furrow across their 
line of march (Fig. 183). The vertical side of the furrow should 
l)e next to the field to be protected and should be smoothed 
by means of a spade. .Every ten or fifteen feet along the bot- 
tom of the furrow post holes a foot or so in depth should be dug. 
When the migrating caterpillars reach the furrow and find 
themselves unable to climb up the smooth side, they crawl 
along the furrow and drop into the post holes, where they may 
be easily and readily killed by crushing or with kerosene oil. 
Any caterpillars that succeed in crossing the barrier may be 
killed by the free use of the poison baits described above. 



CHAPTER XVI 
BLISTER-BEETLES 

The blister-beetles are elongate, long-legged insects which 
in the adult stage frequently attack cultivated crops in swarms. 
They devour the foliage and blossoms and frequently defoliate 
the plants. They usually feed in colonies moving slowly across 
the field and destroying the plants as they go. 

As far as known, the larvse of blister-beetles feed on grass- 
hopper eggs but the life history of most species has not been 
studied. C. V. Riley has given a good account of the early 
stages of the striped blister-beetle, but even in the case of this 
species much remains to be learned. About two hundred 
species of blister-beetles are known to occur in America north 
of Mexico. Less than a score of these have been recorded as in- 
jurious to cultivated plants, but it is quite probable that many 
of the others may on occasion become destructive. 

Most blister-beetles contain a substance, cantharidin, which 
has the property of blistering the skin. The spanish-fly of 
commerce consists of the dried bodies of certain species of 
blister-beetles. 

The Striped B lister-Beetle 

Epicauta vittata Fabricius 

The striped blister-beetle has long been known as an enemy 
of the potato, on which it was formerly more destructive than 

302 



BLISTER-BEETLES 



303 



it has been since the invasion of the Colorado potato beetle. 
It is generally distributed from New England, Quebec and 
Ontario to Montana and southward to Texas and Florida but 
is most abundant in the central and southern states. The 
beetle (Fig. 184) is ^ to f inch in length. In the typical form, 
the head, prothorax and wing-covers are dull yellow or reddish 
yellow. On the head there are two black spots ; on the pro- 
thorax two black stripes, and on each wing-cover two broad 
black stripes. In the variety known as Jemniscata there are 
three black stripes on each wing- 
cover. In Illinois the beetles are to 
be found from the first of June to the 
first of September and are most abun- 
dant during the last half of July and 
the first part of August. They feed 
ravenously on the foliage and blossoms 
of their food plants but have a tend- 
ency to be scattered more uniformly 
through the fields than is the more 
usual habit among blister-beetles. 
They attack potato, tomato, beet, 
eggplant, carrot, cabbage, turnip, 
radish, bean, pea, melon, corn, buck- 
wheat, clover, and in Oklahoma have been found very destruc- 
tive to ripening tomatoes. They also feed on cotton, clematis, 
arrow-leaf and pigweed. 

In Missouri egg-laying begins in Jul\' and may continue 
until October. The female deposits her eggs in clusters of 
about 130 in small excavations in the ground wdiich she hollows 
out and then covers them with earth. The same beetle may 
lay several batches of eggs in the course of her life. The egg 
is about T^ inch in length, smooth and shining, elongate, cylin- 
drical, rounded at the ends and of a pale yellowish color. The 
eggs hatch in ten to twenty-two days. The newly hatched 




Fiu. 184. — The striped 
blister-beetle (X If). 



304 MANUAL OF VEGETABLE-GARDEN INSECTS 

larva is about ^ inch in length and yellowish brown in color ; 
the head is large and provided with a pair of strong jaws. The 
legs are long and slender and the body is elongate and tapers 
toward the tip, which is provided with two long setre. On 
hatching, the young larvae run actively about and biu*row into 
the soil, seeking for grasshopper eggs. They possess great 
vitality and can survive without food for at least three weeks. 
As soon as an egg-pod is found, the larva gnaws its way into 
the capsule and begins feeding on the eggs ; about eight days 
after beginning to feed, the larva molts. The second stage 
larva is white, has a smaller head, shorter legs, and the two 
long setse at the tip of the body have been lost. When in its 
natural position, the larva has its abdomen curled beneath. 
The larva continues to feed on the grasshopper eggs and in 
about a week molts a second time. The third stage larvae 
have the mouth-parts and legs much more reduced, the body 
becomes stouter and thicker and is strongly curved, with the 
head proportionately smaller. The larva grows rapidly and 
takes on a yellowish color, becoming full-grown within the 
egg-pod of the grasshopper. In about ten days after entering 
the egg-pod the larva molts for the third time and about nine 
days later becomes full-grown. In the fourth stage the body 
is more distinctly yellowish. When fully fed, the larva leaves 
the egg-pod and works its way some distance into the surround- 
ing soil. It there constructs a smooth cavity in which it molts 
again but does not completely shed its skin, the latter being 
attached to the posterior part of the body. In this stage the 
insect remains in a dormant condition. The legs and mouth- 
parts are much reduced and are not functional. The skin 
becomes leathery and acquires a deep yellow color. It is about 
I inch in length. In this condition the insect usually hiber- 
nates, and in some cases may remain in this state during a 
second and even sometimes a third winter. In the spring the 
insect molts again. This time the larva resumes the form in 



BLISTER-BEETLES 



305 



which it left the egg-pod but is somewhat smaller and pa!er. 
After moving about in the soil for a few days, it transforms 
to a pupa. The pupal stage lasts about two weeks. There 
is only one brood annually, at least in Illinois and Missouri. 
The striped blister-beetle is a striking instance of an insect 
that is beneficial in one stage of its development and highly 
destructive in another. 



References 

Riley, Trans. Acad. Sci. St. Louis, 3, pp. 544-562. 
Iowa Agr. Exp. Sta. Bull. 1.^5, pp. 377-380. 191^ 



1878. 



The Margined B lister-Beetle 

Epicauta marginala Fabricius 

This blister-beetle (Fig. 185) is a little over ^ inch in length, 
black, with the head and sides of the thorax ashy gray. The 
wing-covers are black, the inner and 
the outer margin with a narro^\■ 
stripe of gray. This beetle is dis- 
tributed throughout the eastern 
United States and occurs sparingly 
in Canada. The larva has been 
found feeding on the eggs of the 
differential locust. The first stage 
larva is about yV ineh in length and 
similar to that of the striped blister- 
beetle. 

The beetles are found from June 
to October. They feed in colonies. 
They have a special fondness for 
beet, but also attack bean, potato, tomato, cabbage, pumpkin, 
clematis, aster, pigweed, ground cherry and wild sunflower. 




Fig. 185. — The margined 
blister-beetle (X 2f). 



306 MANUAL OF VEGETABLE-GARDEN INSECTS 



The Gray Blister-Beetle 



Epicauta cinerea Forster 

The gray blister-beetle (Fig. 186) closely resembles the ash- 
gray species with which it has often been confused. It is 
distinguished by having the second segment of the antennae 

less than one half as long as the 
third. The ash-gray blister-beetle 
is a duller, darker gray ; the gray 
blister-beetle is a lighter gray with a 
slight tinge of yellow. This latter 
beetle has also been confused with 
the margined species, some writers 
even considering the two as merely 
varieties of the same species. While 
the gray blister-beetle is recorded as 
occurring sparingly in the East, it 
is much more abundant in the West 
in Iowa, Colorado, Kansas, Nebraska 
and Texas. It attacks bean, lentil, 
lupine, potato and clover and in western Nebraska has been 
recorded as feeding on the hornbean, locust and honey locust. 
It has been reared from the egg-pods of the Rocky Mountain 
locust. The egg is pale clay-yellow in color, elongate elliptical 
in outline, and about te inch in length. 




Fig. 



ISO. — The gray blister- 
beetle iX 31). 



The Ash-Gray Blister-Beetle 

Macrobasis unicolor Kirby 

The species known as the ash-gray blister-beetle (Fig. 187) is 
i to f inch in length. The ground color is black but the insect 
is clothed with a grayish pubescence so that its general ap- 
pearance is dark gray. The insect is distributed throughout 



BUS TER-BEE TIES 



307 



Canada and the United States westward to Kansas and 
Nebraska. 

The life history of this insect has never been fully worked 
out. The beetles appear in swarms in May or June and are 
more or less abundant until autumn. 
The female lays her eggs in irregular 
masses in the ground an inch or so 
below the surface. The beetles have 
been rearefl from larvie feeding on the 
eggs of the Rocky Mountain locust. 
In Minnesota there are said to be two 
generations annually, the adults of the 
first brood appearing about the middle 
of June, those of the second from the 
middle of August to early in September. 
These beetles are especially fond of 
leguminous plants, pea, bean, soybean, 
cowpea, clover, alfalfa, black locust, 
honey locust, wild indigo, lupine and 
astragalus. They also attack potato, tomato, sweet potato, 
beet, radish, flax and several wild plants. 




Fi(i. 187. — The ash-gray 
blister-beetle (X 4^). 



The Black Blister-Beetle 

Epicauta pennsylvanica De Geer 

This insect (Fig. 188) is ^ inch or less in length and of a uni- 
form, dull black color. It is widely distributed throughout 
the eastern United States and Canada east of the Rocky Moun- 
tains. It attacks a large variety of plants, including potato, 
tomato, carrot, mangel, cabbage, corn, onion, chrysanthemum, 
pink, aster, clematis, passion flower, zinnia and alfalfa. It 
also feeds on pigweed, thoroughwort, ragweed and meadow rue. 

This blister-beetle usually becomes abundant a little later 
in the season than the other common species. The egg is pale 



308 MANUAL OF VEGETABLE-GARDEN INSECTS 



clay-yellow, elongate elliptical and slightly less than to' inch 
in length. The eggs are deposited in clusters of eighty to over 
one hundred in the ground in late 
summer or fall. They hatch in two 
or three weeks. The first stage larva 
is black, about t2" inch in length and 
in structure resembles that of the 
striped blister-beetle. The larvae feed 
on grasshopper eggs, adults having 
been reared from larvse found in the 
egg-pods of the Rocky Mountain locust. 
There is only one brood annually. 

/^j ^H "X On the Pacific Coast a closely related 

^Hjjl^ ^ black blister-beetle, Epicauta puncti- 
Pi 188 _ The black coIUs Mann, has been reported as 
blister-beetle (X 3|). injurious to potato and aster. 




Nuttall's Blister-Beetle 

Cantharis nutlalli Say 

The head and prothorax of Nuttall's blister-beetle (Fig. 189) 
are green, often with coppery or purplish 
reflections, and the insect is from f to 1 
inch in length. The wing-covers vary 
from dark purplish green to a rich bronzy 
purple. The antennae and legs are dark 
greenish or bluish. The underside of the 
body is dark green. This beautiful beetle 
ranges from Saskatchewan southward west 
of the INIississippi and east of the Rockies 
to New Mexico. The life history has not 
been worked out but the larvae are sup- 
posed to feed on grasshopper eggs. The ^^^^ ^^g _ Nuttall's 
beetles often appear in swarms and devour blister-beetle (x I2). 




BLISTER-BEETLES 



309 



the foliage of beans, beets, alfalfa, vetch, oats and barley. 
The beetles appear at irregular intervals, some years being 
very rare. In the northern part of their range, they may be 
expected from the middle of June to the last of July and some- 
times continue until fall. 



The Spotted B lister-Beetle 

Epicaula maculata Say 

The spotted blister-beetle (Fig. 190) is ^ inch or less in 
length, light gray in color with the wing-covers marked with 
numerous small round black spots where 
the pubescence is lacking. This blister- 
beetle ranges from western Canada 
southward through Montana, South 
Dakota, Kansas, Nebraska and Okla- 
homa to New Mexico and westward to 
Washington, Oregon and California east 
of the Cascade Mountains. The beetles 
attack potato, bean, beet, cabbage, 
spinach, alfalfa and clover. They have 
also been recorded as feeding on lamb's 
quarters and grease-wood. In British 
Columbia the beetles are abundant from 
the middle of May till the middle of 
August. The early stages have not been described. 




Fi<;. 190. — The 
blister-beetle ( 



.s|j()tted 
X3). 



The Two-Spotted B lister-Beetle 

Macrobasis albida Say 

This beetle (Fig. 191) is nearly an inch in length, uniform light 
gray, with two elongate black spots on the prothorax. The 
basal part of the antennae is yellowish or reddish. This species 
ranges from Kansas to Texas and westward to Arizona. It 



310 MANUAL OF VEGETABLE-GARDEN INSECTS 



has been reported as injurious to potato, tomato, pea and sugar- 
beet. 

A closely related species, Macrobasis longicollls Leconte 
(Fig. 192), lacking the two black spots on the prothorax, has 





Fig. 191. — The two-spotted 
blister-beetle (X 11). 



Fig. 192. — Macrobasis 
longicollis ( X 2). 



been recorded as very destructive to potatoes and alfalfa in 
New Mexico. 

Miscellaneous Blister-Beetles 

The immaculate blister-beetle, Macrobasis immaculata Say, 
is uniform yellowish gray in color and is nearly an inch in length. 
It has been reported as injurious in Kansas and Colorado. It 
feeds on potato, tomato and cabbage. 

The segmented black blister-beetle, Macrobasis segmentata Say, 
is large and black, from f to an inch in length. It has been 
recorded as injurious to beet, potato, tomato and cabbage in 
Kansas. Its range extends into Mexico. The beetle is dull 
black in color, usually with a narrow band of lighter hairs on 
the front and hind margins of the prothorax. The underside 
of the abdomen is ringed with a narrow band of light hairs on 
the hind margin of each segment. 



BLISTER-BEETLES 



311 



Tfie larc/e black blisfrr-hcetlr, Lytta hisperata Horn (Fig. 193). 

In southern California sugar-beets are sometimes seriously 

injured by this shining black blister- 
beetle, about f inch in length. The 

dorsal surface often has a rich, bluish 

metallic luster and there is a small red 

spot on the middle of the face just 

above the eyes. 

The panther blistcr-becflc, Kpicauta 

pardalis Leconte (Fig. 194), is a little 

less than ^ inch in length, light silvery 
gray and covered 
with numerous 
(• )nfluent black 
spots on which the 
pubescence is lack- 
ing. It has been reported as a serious 
pest of potatoes in Arizona, where it 
appears in the fields about the first of 
July. 

The croiv blister-beetle, Kpicauta cor- 

rina Leconte, is large and black, 

^, nearlv an inch in length. It has been 

Fic. 194. — The pan- ' ... 

thcr blister-beetle reported as injurious to potatoes m 
^^^*)- Arizona. 





Fi(i.U);5. — The iar«o 
l)kick hlistcr-bectlo (X 2). 



Means of Controlling Bllster-Beetles 



Blister-beetles are difficult to control because they are in- 
jurious in the adult stage. They fly readily from one plant 
to another and are not easily poisoned with arsenicals. In 
the garden, screening choice plants with mosquito netting and 
hand-picking the beetles into pans containing a little kerosene 
are practical methods of preventing injury. On potatoes and 



312 MANUAL OF VEGETABLE-GARDEN INSECTS 

other crops on which paris green and arsenate of lead can be 
safely used, spraying is the most practical measure to- be em- 
ployed. The poison should be applied at the first appearance 
of the beetles, using 1 pound of paris green or 3 or 4 pounds of 
arsenate of lead (paste) to 50 gallons of water. One pound 
of lime should be added to each pound of paris green to lessen 
the danger of burning the leaves. The arsenicals may be 
used to advantage somewhat stronger^ provided the plants 
are not injured. In some cases in which it is not possible to 
use an arsenical poison, the beetles may be driven before the 
wind into windrows of hay or straw along the edge of the field 
and then burned. 



CHAPTER XVII 
FLEA-BEETLES 

Among the most troul^k'some of garden pests are several 
species of small, usually dark-colored leaf-beetles which have 
the hind femora enlarged for jumping. When alarmed they 
spring suddenly into the air to a distance of a foot or more and 
thus escape the pursuer. This habit of jumping has given the 
insects the highly appropriate name of flea-beetles. Flea- 
beetles, as a rule, eat out pits or holes in the leaves, causing the 
death of the surrounding tissue. Badly injured leaves become 
riddled with holes, turn brown and die. The beetles are most 
destructive to young plants early in the season. In most 
species the larvae feed on the roots, but in some cases they may 
live as miners in the leaves or as borers in the petioles. Usually 
the beetles hibernate in dry sheltered places, under the bark 
of trees, under rubbish and in hedgerows. It often happens 
that their injuries to cultivated crops are first apparent along 
the edge of the field nearest to such shelter. Some species are 
closely restricted to one or two food plants, while others attack 
a large variety of plants in widely separated families. As 
a rule, however, each species shows a decided preference for 
some particular group. For instance, one prefers the cabbage, 
turnip, mustard and then- relatives, another is more or less 
restricted to the potato and other solanaceous plants, while 
a third is partial to the beet, spinach, lamb's quarters and others 
of the same family. 

313 



314 MANUAL OF VEGETABLE-GARDEN INSECTS 



The Potato Flea-Beetle 



Epitrix cucumeris Harris 

This insect is also known as the cucumber flea-beetle because 
it was first described from specimens feeding on that plant. 
But,' as it is an important pest of the potato and feeds only 
sparingly on cucumbers, it is more appropriately called the 
potato flea-beetle. This species is distributed throughout the 

United States and 
Canada from the 
Atlantic to the 
Pacific and has 
been reported from 
Porto Rico. It is, 
as a rule, more 
abundant and de- 
structive in the 
more northern part 
of its range. It is 
second only to the 
Colorado potato 
beetle as an enemy 
of the potato and 
in many localities 
has proved itself, 
on the whole, more 
injurious. It also 
attacks tomato, 
eggplant, wonder- 
berry (Solanum 
nigrum), peppers, turnip, radish, cabbage, celery, beet, water- 
melon, cantaloupe, tobacco, cucumber, petunia, bittersweet 
{Solanum Dulcamara), Jerusalem cherry, horse-nettle (Solanum 




Fig. 195. — Potato leaves injured by the potato 
flea-beetle. 



FLEA-BEETLES' 315 

carolinese), common nightshade, ground cherry (Physalis), 
Jimson weed and sunflower. It has also been recorded as 
injuring young corn plants. The beetles feed on both the 
upper and under surface of the leaves, eating out small round 
holes through the epidermis and parenchyma but usually 
leaving the epidermis on the opposite side intact. This soon 
dies and breaks away, leaving the foliage ritldled with small 
holes. Badly injured leaves first turn yellow, then brown, 
curl up and die (Fig. 195). 

The potato flea-beetle is one of the smallest species of the 
group. It is from iV to ts" inch in length, black, with the 
antennffi and legs brownish yellow. The 
hind femora and part of the middle and 
front femora are black. The prothorax 
has a deep transverse depression near the 
hind margin (Fig. 196). The jxisteriir 
femora are greatly enlarged, giving the 
insect the power to jump a considerable 
distance. The beetles pass the winter in 
sheltered places under rubbish and are 
found in the spring on plantain and other ^'flei^beetie^'x T-i)''*" 
weeds as well as on the foliage of apple, 
wild cherry and maple. As soon as their cultivated food 
plants come up or are transplanted into the field, the\' are 
subject to attack. Tobacco and cabbage plants may be 
seriously injured in the seed-bed. On Long Island the 
beetles begin egg-laying the early part of June and in ]\Iaine 
the latter part of the month. The egg is about ttct inch in 
length, elongate ellipsoidal and white in color. The eggs 
are deposited in the soil around the plants. At this time the 
beetles are sometimes found four or five inches in the ground 
but whether they enter the soil for egg-laying is not known. 
The larvai feed on the roots, tubers and underground stems of 
the plant and are sometimes found on the piece of potato used 




316 MANUAL OF VEGETABLE-GARDEN INSECTS 

for seed. The full-grown larva is about i inch in length with 
a brown head and yellowish brown thoracic shield. The 
larvae are sometimes found with the front part of the body 
inserted into the tuber, from which the remainder of the body 
projects. The tissue surrounding the larva in the tuber be- 
comes hardened and turns blackish. Under some conditions 
the presence of the grub causes an abnormal growth on the 
surface of the tuber about i to i inch in diameter, low, convex 
and scurfy at the top. Tubers so affected are called pimply 
potatoes and their market value is considerably lessened. 
The larvae have also been found feeding on the roots of tomato, 
eggplant and the common nightshade. When mature they 
transform within small earthen cells to whitish pupse about 
TS" inch in length and in six to eight days transformation to 
the adult takes place. On Long Island the beetles of the new 
brood begin to appear in early July and in ]Maine about the 
middle of the month. Some of the beetles continue feeding 
until cold weather, when they go into hibernation. Nearly 
all the females do not oviposit until the following spring, but 
it is quite probable that a few of them soon after emerging 
lay eggs from which there is produced a small second brood 
of beetles in late summer or early fall. This second brood 
goes into hibernation with those of the preceding generation. 

The beetles that have hibernated feed ravenously until the 
eggs have been laid and then gradually decrease in numbers. 
Thus, during late June and early July, they are much less abun- 
dant in the field than earlier in the season or a little later when 
the beetles of the new brood begin to appear. The dying off 
of these over-wintered beetles has often misled growers into 
thinking that they had been killed by spraying. 

While the larvae are sometimes injurious to the tubers, this 
type of injury is not common. The most serious injury is to 
the foliage. Not only is the leaf surface greatly reduced by 
the feeding of the beetles and the consequent killing of the 



FLEA-BEETLES 317 

leaves, but the punctures serve as points for infection by the 
early potato blight fungus. The injury to the foliage also has 
a direct influence on the size and quality of the tubers. Injury 
by flea-beetles is most pronounced during dry seasons when 
the plants are least able to withstand the loss of their foliage. 
Tomato j)lants are most subject to injury when first trans- 
planted. 

Means of control. 

On potatoes flea-beetle injury is best held in check by keep- 
ing the plants well covered with bordeaux mixture. Frequent 
and thorough spraying with this material not only makes the 
plants distasteful to the beetles but also protects them from 
infection by the potato blight fungus. Experience has shown 
that spraying with paris green or arsenate of lead, as for the 
Colorado potato beetle, is of little or no value in destroying 
the potato flea-beetle, because the latter either avoids the 
poison or eats so little of it as to be unaffected. Where an 
arsenical is used in bordeaux mixture for the control of the 
Colorado potato beetle, it is quite probable that many of the 
flea-beetles are also poisoned, but it is a question whether 
enough of them are killed to make it worth while to add the 
poison for flea-beetles alone. It has been suggested that 
sweetening the poison might make it more attractive but 
experiments on Long Island have shown that repeated appli- 
cations of sweetened arsenate of lead in bordeaux mixture are 
injurious to the potato plants. When potatoes are thoroughly 
sprayed every ten to fourteen days with bordeaux mixture 
for the control of potato blight, a practice now commonly 
followed by commercial potato-growers, it is possible to raise 
a good crop in spite of the flea-beetle. Tomato plants are 
most seriously injured by flea-beetles soon after transplanting 
and should be kept well sprayed with bordeaux mixture until 
the danger is past. 



318 MANUAL OF VEGETABLE-GARDEN INSECTS 

Cabbage plants are often seriously injured in the seed-bed. 
This may be avoided by screening the beds as described for 
the control of the cabbage root-maggot (page 35). 

References 

N. Y. (Geneva) Agr. Exp. Sta. Bull. 113. 1896. 

Maine Agr. Exp. Sta. Bull. 211. 1913. 

Iowa Agr. Exp. Sta. Bull. 155, pp. 367-376. 1915. 



The Western Potato Flea-Beetle 

Epitrix subscrinita Leconte 

On the Pacific Coast, the potato flea-beetle is replaced by this 
closely related species which may be distinguished by its bronzy 

brown color (Fig. 197). It has been 
reported from California to British 
Columbia, where it is an important 
pest of the potato, tomato, pepper 
and eggplant. It also attacks the 
bean. Among its wild food plants 
are many common weeds. The 
beetles spend the winter under rub- 
bish. They appear in March and 
April, feeding at first on weeds and 
later on cultivated crops. The larvfe 
feed on the roots and tubers of potato 
and also bore a short distance into the latter. The full-grown 
larva is about | inch in length, slender, and white with a 
brown head. In Oregon the larvae become mature in late 
June, transform to small white pupse within earthen cells 
early in July, and the beetles begin to emerge the latter part 
of the month. These beetles soon lay eggs for a second brood 
of larvae, which pupate in September, giving rise to another 
brood in October. After feeding for a time on the foliage, 




Fig. 197. — The western po- 
tato flea-beetle (X 16). 



FLEA-BEETLES 319 

these insects go into hibernation probably in company with 
same of the beetles of the previous generation. There are 
probably two broods annually. 

This western potato flea-beetle may be controlled by the 
measures suggested for its eastern relative. 

On the Pacific Coast potatoes are also attacked by another 
flea-beetle, Glyptina cerina Leconte. 

Reference 
Ore. Agr. Col. Bull. 91, pp. 11-13. 1913. 

The Tobacco Flea-Beetle 

Epitrix par villa Fabricius 

This near relative of the potato flea-beetle ranges from ]\Iary- 
land to INIichigan, Colorado and Wyoming and southward to 
Texas, Florida, Central America and the West Indies. It 
also occurs in California and Hawaii. This flea-beetle is a 
serious enemy of tobacco but also attacks potato, tomato, 
eggplant, and among wild plants feeds on horse-nettle, ground 
cherry and Jimson weed. In California it has been known to 
attack almond, orange and squash. In Hawaii it injures the 
cape gooseberry. Its injuries to potato, tomato, and eggplant 
are similar to those inflicted by the potato and eggplant flea- 
beetles with which it is often associated. 

The tobacco flea-beetle is about ts inch in length, yellowish 
brown, usually with a darker band across the middle of the 
wing-covers ; the antennae and legs are also yellowish brown 
except the femora, which are somewhat darker. The trans- 
verse depression near the hind margin of the prothorax is only 
faintly indicated (Fig. 198). The beetles emerge from hiberna- 
tion in the spring and attack the plants as soon as they come up. 
The eggs are probably deposited in the soil at the base of the 



320 MANUAL OF VEGETABLE-GARDEN INSECTS 

plants. The egg is about eV inch in 
length, pale yellowish gray in color and 
elongate oval in outline. The larvae feed 
on the roots and stems below ground and 
pupate in the soil an inch or so from 
the surface. After about a month from 
the time the egg was laid the beetle 
appears. The number of generations 
annually has not been determined but in 
California there are said to be several. 
The tobacco flea-beetle can be controlled by the measures 
suggested for the potato flea-beetle. 

Reference 
U. S. Div. Ent. Bull. 19, pp. 85-87. 1899. 




Fio. 19S. — The tobacco 
flea-beetle (X 18). 



The Eggplant Flea-Beetle 

Epitrix fuscula Crotch 

This species is also closely related to the potato flea-beetle. 
It ranges from New Jersey through Illinois, Nebraska and 
Utah to California and southward to 
Georgia and Louisiana. In size and 
general appearance, it closely resembles 
the potato flea-beetle but all the femora 
are black, the transverse depression near 
the hind margin of the prothorax is less 
distinct and the wing-covers are slightly 
more hairy (Fig. 199). The beetles 
come out of hibernation in early spring, 
as early as March 20th in Indiana. 
They show a decided preference for 
eggplant but have also been found injurious to potato and 
have been recorded as feeding on horse-nettle, hazelnut, poke- 
weed, sugar-beet and strawberry. 




Fig. 199. — The egg- 
plant flea-beetle (X IC). 



FLEA-BEETLES 



321 



This flea-beetle may be controlled by the same measures as 
suggested for the potato flea-beetle. 



The Pale-Striped Flea-Beetle 

Sy.'^lcna tccniata Say 

This abundant and widely distributed flea-beetle is very 
variable in coloration and sculpture. Several varieties have 
been described, some of which are considered as distinct species 





Fig. 200. 



— The pale-striped flea- 
beetle (X 13). 



Fic. 201. — The pale-striped flea- 
beetle, variety hlanda (X 13). 



by certain writers. The beetle is about i inch in length ; the 
antennjfi and legs are reddish or yellowish brown ; the head 
is reddish, and the thorax brownish. In the typical form the 
wing-covers are black with two pale yellowish longitudinal 
stripes. In the light-colored variety, hlanda, the thorax and 
wing-co^•ers are paler and the wing-covers have the pale stripe 
much broader, often leaving but little of the dark markings. 
In some specimens the wing-covers are uniformly pale. All 
gradations occur (Figs. 200 and 201). 



322 MANUAL OF VEGETABLE-GARDEN INSECTS 

The insect ranges from New England throngli Canada to 
California and southward to Georgia, Alabama and Mexico. 
It has been found most destructive to young beets and recently 
transplanted tomato plants. It also attacks potato, carrot, 
parsnip, cantaloupe, cucumber, pumpkin, cabbage, turnip, 
radish, pea, bean, eggplant, lettuce, summer savory, sweet 
potato, peanut, corn and cotton. It feeds on a large number 
of wild plants, among which are pigweed, lamb's quarters, 
purslane, ragweed, cocklebur, horse sorrel and wild solana- 
ceous plants. It also sometimes injures newly set aster plants 
and apple and pear nursery stock. 

It is not definitely known where or in what stage the insect 
passes the winter. The beetles appear on the plants in the 
spring. In feeding they eat out small holes in the epidermis 
and parenchyma but do not eat through the leaf. Young 
beet plants are often killed in this way, it sometimes being 
necessary to replant. The egg is about tV inch in length, 
elliptical in outline, and yellowish in color. The eggs have 
not been observed except under cage conditions. Larvie have 
been found on the roots of lamb's quarters and probably occur 
on several other common weeds. A single larva was once 
found on a sprouting corn plant. This may have been acci- 
dental. The full-grown larva is elongate, about i inch in length, 
white, with a yellowish head. The body is broadest posteriorly. 
At Washington the eggs are laid during June and July and the 
adults of the new brood begin to emerge in late July. The 
number of generations annually has not been definitely de- 
termined but there is probably only one, at least in the North. 
The insect probably hibernates as a larva, pupates in the 
spring and transforms to the adult in May or June. 

References 

U. S. Div. Ent. Bull. 23, pp. 22-29. 1900. 

111. Agr. Exp. Sta. Bull. 60, pp. 468-470. 1900. 



FLEA-BEETLES 



323 



The Red-Headed Flea-Beetle 



Systena frontalis Fabricius 

This species closely resembles the smartweed flea-beetle 
from which it may be distinguished by its reddish head (Fig. 
202). It ranges throughout the 
United States and Canada east of 
the Rockies and south to Florida. 
Outbreaks of this beetle are usually 
more or less local but serious injury 
may sometimes result. It attacks 
potato, beet and bean, and in 
Canada is sometimes destriu'ti\'c 
to the second crop of clover. 
Yoinig grape vines are occasionally 
nearly defoliated by the beetles. 
They have also been known to 
attack cranberry, rose mallow, 
marsh mallow, Japanese honey- 
suckle, weigela, aster and chrysanthemum. Among weeds 
they are known to feed on smartweed, lamb's quarters and 
pigweed. 

The beetles have been found hibernating under the loose 
bark of trees and in mullein rosettes. The early stages have 
not been described. 




l'"i<;. 21)2. — The rod-hoiulcrl 
flea-beetle (X 8). 



The Smartweed Flea-Beetle 

Systena hudsonias Forster 

This elongate bluish black flea-beetle is generally distributed 
throughout the United States and Canada east of the Rocky 
Mountains where it has been recorded as injurious to potato, 
bean, corn, beet and cabbage plants in the seed-bed. It has 



324 MANUAL OF VEGETABLE-GARDEN INSECTS 



also been known to injure cranberries and grapes as well as 
apple and pear grafts. The beetles feed on a wide variety of 
weeds, including smartweed, pigweed, daisy, fleabane, ragweed, 

plantain, catnip, dock and 
goldenrod. 

The beetle is slightly more 

than i inch in length, and bluish 

black in color, with the antennae 

having the two basal segments 

dark, the next three or four 

light and the remainder dark 

(Fig. 203). They are most 

abundant in midsummer. The 

immature stages have not been 

described and the number of 

broods occurring annually is not 

known. 

When attacking cabbage in the seed-bed, the injury is best 

prevented by screening the bed with cheesecloth as is often 

done for protection against the cabbage root-maggot (page 35). 




Fig. 203. — The smartweed flea- 
beetle (X 11). 



The Striped Cabbage Flea-Beetle 

Phyllotreta villata Fabrieius 

The striped cabbage flea-beetle shows a preference for crucif- 
erous plants, attacking cabbage, radish, turnip, horse-radish, 
water-cress, stock and wall-flower. It is also recorded as injuri- 
ous to tomato and strawberry. Its most important unculti- 
vated food plant is the wild mustard, but it also feeds on 
charlock, shepherd's purse and rocket. The insect ranges 
throughout the United States and southern Canada east of the 
Rocky Mountains. The beetles hibernate in sheltered places 
and appear in the fields in the spring, in western New York 
about the middle of May, The adult is about yV ii^ch in length, 



FLEA-BEETLES 325 

black, witli each ^vln2;-C()^'cr marked with a wavy yellowish 
stripe, narrowed in the middle and incurved at each end (Fig. 
204). The beetles are most destructive to cabbage plants be- 
fore the fourth leaf has appeared or during the first week after 
they come up. They gnaw pits in the leaves but do not eat out 
holes except in very thin leaves. Young cabbage, turnip and 
radish plants are often killed in this way. The females deposit 
the minute, oval, whitish eggs at the base of the plant in irreg- 
ular excavations gnawed out in the root near the crown. The 
lar\'ie feed on the roots of cabbage and 
radish and in New York have been found 
especially abundant on the roots of the 
wild mustard. The larva? eat off the 
smaller roots and riddle the main one 
with tunnels, sometimes excavating the 
entire root. The full-grown larva is 
al)out i inch in length, whitish with a 
light brown head. In Illinois the larvte 
are present in late Mav and June and Fig 204. - The striped 

^ 1 c 1 1 • 4 cabljago flea-beetle 

give rise to a brood or beetles in August. (x 13). 

The over-wintered beetles mostly <lis- 

appear in June and in the North turnips sowed after this date 

are likely to escape injury. In North Carolina a second brood 

of larvffi has been observed on turnips in October. In Illinois 

there is said to be but one generation annually but in North 

Carolina there are at least two. 

Cabbage plants in the seed-bed are very liable to injury 
by this flea-beetle. They may be protected by screening the 
beds with cheesecloth as recommended for the cabbage root- 
maggot (page 35). 



Reference 
Shimer, Ameriean Naturalist, 2, pp. 514-517. 1869. 




326 MANUAL OF VEGETABLE-GARDEN INSECTS 

In California a closely related species, PhyUotreta ramosa 
Crotch, in which the yellowish stripe on the wing-cover has a 
short branch just back of the middle, has been reported as in- 
jurious to turnip, radish and mustard. 

The four-spotted cabbage flea-beetle, PhyUotreta bipustulata 
Fabricius, is sometimes found feeding on cabbage and turnip 
in the Atlantic states. Its wild food plants are hedge mustard, 
charlock and shepherd's purse. It has never been known to 
cause any serious injury. In this species each wing-cover is 
marked with two large yellowish spots. 

In California cabbage, radish, mustard and turnip are some- 
times attacked by a small, dark, metallic green flea-beetle, 
Ilemiglyptus basalis Crotch. 



The Sinuate-Striped Flea-Beetle 

PhyUotreta sinuaia Stephens 

This flea-beetle is often found in company with the striped 
cabbage flea-beetle, feeding on cabbage, turnip and radish. 
The insect was probably introduced from 
Europe but is now widely distributed 
throughout the United States and Canada. 
The beetle averages somewhat larger than 
the striped cabbage flea-beetle and the 
yellowish stripe on the wing-cover does 
not turn inward toward the base, being 
nearly parallel with the inner margin 
(Fig. 205). The eggs are deposited singly 
on the upper surface of the leaf along the 
midrib. The egg is t¥s inch in length, 
dull greenish white, depressed, oblong 
and glued to the leaf by one side. The 
larvae have been found as miners in the leaves of wild pepper- 
grass, cress and rock cress. The young larvae enter the leaf, 




Fig. 205.— The .'sinuate- 
striped flea-beetle 
(X 14). 



FLEA-BEETLES 



327 



where they eat out a mine of the liloteh type, often being 
numerous enough to kill the phmt. The full-grown larva is 
about i inch in length, orange, with the head, pronotum and 
anal segment dark brown. The other segments are marked 
with numerous brown spots. When mature, the larva descends 
to the ground, where in an earthen cell, it transforms to a 
white or yellowish pupa. In May and June in Missouri the 
life cycle from egg to adult requires about three weeks. This 
species has not been recorded as causing any very serious in- 
jury. This may be explained in i)art from its being frequently 
mistaken for the striped cabbage flea-beetle. 

Reference 
Riley, U. S. Ent. Rept. for 1881, pp. 304-308. 

The Western Cabbage Flea-Beetle 



Phyllotrctn pusilla Horn 

Along the eastern slope of the Rocky Mountains from Dakota 
to Mexico and in New Mexico and southern California, the 
wavy-striped flea-beetle is replaced 
by this pitchy black, slightly bronzy 
beetle from xs to iV inch in length 
(Fig. 20()). It has been recorded 
as injurious to cabbage, radish, 
turnip, horse-radish, mustard, rape, 
pea, sugar-beet and corn. It also 
feeds on hedge mustard and the 
bee plant. The beetles hibernate 
and are most destructive to the 
young plants soon after coming 
out of hibernation. The early 
described. 




Fk;. 206. — The western cab- 
bage flea-beetle (X 16). 

stages have not been 



328 MANUAL OF VEGETABLE-GARDEN INSECTS 



The Horse-Radish Flea-Beetle 



Phyllotrcia armoracicc Koch 

Imported from Europe about 1893, this horse-radish pest 
is now present in the northern states from New York and New 
Jersey to Iowa and Nebraska. It has also been found at 
■Montreal, Canada. In some localities it has already proved 
itself a serious enemy of horse-radish, making it necessary to 
replant the beds yearly. In contrast 
to the habits of many other flea- 
beetles, this insect has a very re- 
stricted list of food plants, including 
only marsh cress in addition to horse- 
radish. The winter is passed by the 
beetles in dry sheltered places. The 
adult (Fig. 207) is about i inch in 
length, oval, strongly convex, black in 
color, with each wing-cover yellowish, 
except a narrow black stripe along 
the outer margin and a wider one on 
the inner margin, the latter broadest 
at the middle. The antenna are 
yellowish at the base. The legs are yellowish except the 
hind femora and all but the tip of the front and middle 
tibise, which are black. The beetles appear on the plants 
early in the spring and eat out holes in the leaves and 
cavities in the midribs. The female deposits her smooth, 
oval, orange eggs, about to inch in length, in clusters of twenty 
or more, loosely attached to the petioles of the young leaves. 
Egg-laying begins in late April or May and may continue until 
August. Each female usually lays several batches of eggs and 
the total number laid by a single individual may exceed 400. 
The eggs hatch in a week or two. On hatching, the young 




Fig. 207. — The horse- 
radish flea-beetle (X 9). 



FLEA-BEETLES 329 

larva enters the petiole, where it burrows through the tissue, 
often causing the death of the leaf. Its presence is indicated 
by brownish, dead areas where the larva has come near the 
surface. The mature larva is nearly i inch in length, slender, 
pale yellowish white, with the head, thoracic shield and anal 
plate dark brown. From seven to over nine weeks are required 
for the larva to reach maturity. It then descends to the ground, 
where it transforms to a small white pupa in an earthen cell 
and in ten days to two weeks the beetles emerge. There is 
only one brood annually. The beetles are more destructi\e 
early in the season and the larvae later. The foliage is injured 
to such an extent that the roots do not develop and the croj) is 
consequently shortened. 

Control. 

The plants may be made distasteful to the beetles and some 
of them poisoned by thorough spraying with bordeaux mixture 
containing 4 or 6 pounds of arsenate of lead (paste) in 50 gallons. 
When the pest is abundant, several applications at intervals 
of two or three weeks may be found necessary. In some cases 
it is advisable to change the location of the beds yearly to new 
land in order to escape attack by the beetles. 

Reference 
U. S. Dept. Agr. Bull. 535. 1917. 

The Spinach Flea-Beetle 

Disonycha xanthomelccna Dalman 

So far as known, this flea-beetle has been injurious only to 
beet, spinach and salt-bush. Its wild food plants include 
lamb's (|uarters, pigweed and chick-weed. The insect is dis- 
tributed throughout the United States and Canada east of the 
Rocky JVIountains. 



330 MANUAL OF VEGETABLE-GARDEN INSECTS 



The beetle is about i inch in length, greenish black in color 
with the prothorax yellow (Fig. 208). The insect hibernates 
in the adult stage and appears in the field early in the spring. 
The female deposits her elongate, elliptical, orange eggs, from 
aV to XT inch in length, on end, in clusters of about thirty on 
the ground at the base of the plant. Each female may lay 
several batches of eggs at intervals of a few days. The larva 
escapes through a slit in the side of the egg near the base. The 
young larva is nearly ^ inch in length, uniform light gray and 

armed with numerous black 
spines which are white at 
the tip. The young larvse 
crawl to the plants and feed 
on the underside of a leaf, 
at first gnawing off only the 
surface but later eating out 
holes. When alarmed, the 
larvae fall to the ground, 
where they remain hidden 
until the danger is past. 
The young larvae have the 
habit of feeding in colonies 
but when older become scattered. After the tops are killed, 
they may feed on the roots. The mature larva is a little more 
than I inch in length, leaden gray, with head and mouth-parts 
brownish. When feeding on beets, it acquires a purplish color. 
The larva becomes full-grown in ten days to a month. It 
then enters the ground and transforms to a grayish pupa in a 
slight earthen cell near the surface. In six to nine days the 
transformation to the adult takes place and after waiting a 
day or two to become hardened the beetle emerges. At 
Washington there are two generations annually. Egg-laying 
by the new brood of beetles begins the latter part of July 
and continues until September. 




Fig. 208. 



The spinach flea-beetle 
(X71). 



FLEA-BEETLES 331 

Reference 
U. S. Div. Ent. Bull. 19, pp. 80-85. 1899. 

The Yellow-Necked Flea-Beetle 

Disonycha mellicollis Say 

This beetle is found from New Jersey, Indiana and Colorado 
southward to Florida and Texas. It is closely related to the 
spinach flea-beetle, from which it maybe distinguished by having 
all the femora reddish or yellowish. It has been recorded as 
injurious to beets and spinach in Texas and Florida. Its wild 
food plants are amaranth and purslane. The beetles come out 
of hibernation early in the spring and deposit their blood-red 
eggs, similar to those of the spinach flea-beetle, in clusters of 
forty or fifty on the leaves or on the ground at the base of the 
food plants. The eggs hatch in four to ten days. The larvce 
feed on the underside of the leaves, injuring the plant in much 
the same way as do those of the spinach flea-beetle. They 
become full-grown in about eleven days and are then dull 
yellowish red. Pupation takes place in the ground and the 
beetles emerge in about five days. 

Reference 
V. S. Bur. Ent. Bull. 82, pp. 29-;i2. 1909. 

The Three-Spotted Flea-Beetle 

Disonycha triangularis Chevrolat 

This closely related species ranges through the United States 
and Canada east of the Rocky Mountains. It has been re- 
ported as injurious to beets, mangels and sugar-beets. Its 
wild food plants are lamb's (piarters and spiny pigweed. The 
beetle is ^ to ^ inch in length, bluish black; the prothorax is 



332 MANUAL OF VEGETABLE-GARDEN INSECTS 




yellow, marked with three blaek 
spots arranged in a triangle (Fig. 
209). The inseet hibernates as a 
beetle in sheltered places. The early 
stages have not been described. 

The Larger Striped Flea-Beetle 



Disonycha crenicollis Say 
Fig. 209. — Tlie tlucc-spotted , . . • i tt • i 

flea-beetle (X 5). ihis species occurs ni the United 

States east of the Rocky Mountains, 
ranging from New York to Nebraska and south to Mexico. 
The beetle is abaut -j inch in 
length, yellow, with two black 
spots on the prothorax and 
has each wing-cover marked 
with a narrow marginal and 
sutural, and a brt)ader median 
black stripe (Fig. 210). It 
has been found on beet, melon 
and strawberry in Illinois. It 
hibernates in the adult con- 
dition and the early stages ^^ ^m t-i i * ■ ^a 

•^ ^ Fig. 210. — The larger striped nea- 

are unknown. beetle (x 41). 




The Sweet Potato Flea-Beetle 

Chcetocnema confinis Crotch 

Although this flea-beetle is widely distributed throughout 
the United States east of the Rocky Mountains and has also 
been taken in California, it has attracted most attention by 
its injuries to the sweet potato in New Jersey. In some local- 
itie;s and in certain seasons, it has proved itself the most im- 



FLEA-BEETLES 333 

portant insect enemy of that crop. It has been observed feed- 
ing on sugar-beet, corn, wheat, oats, timothy, blue-grass, buck- 
wheat, red clover, raspberry and box elder. 

The beetle is about ts inch in length, pitchy black with a faint 
bronzy reflection. The antennae and legs, except the hind 
femora, are reddish yellow (Fig. 211). The winter is passed 
by the beetles in rubbish, especially along hedgerows and 
woodlots. In New Jersey they appear on the sweet potato 
plants as soon as transplanted in May. They do not eat holes 
through the leaves but eat out grooves or channels in the 
upper surface, usually beginning along 
the mure prominent veins. Later a large 
part of the surface may be eaten oflF; the 
leaf wilts, turns brown and dies. Young 
plants are often killed in this way or so 
badly stunted that they do not produce a 
good crop. In New Jersey the beetles 
are most abundant in May and the first 
part of June, when they begin to leave Fig. 211. — The sweet 
sweet potato, and by the first of July p^J^^*" flea-beetle 
very few are left. On leaving the sweet 
potato, they migrate to bindweed, which is often found groov- 
ing as a weed in the fields or along the fences. It is on this 
plant that the larvte have been found feeding on the fine 
roots but not tunneling the larger roots. When full-grown, 
the larva is about | inch in length, white, with a brown- 
ish head. The whitish pupie are found in earthen cells in the 
ground. The beetles of the new brood begin to appear in late 
July but do not return to the sweet potato in large numbers until 
the following spring. There is only one generation annually. 

Control. 

Fortunately this flea-beetle dt)es not attack sweet potato 
plants in the seed-bed to any appreciable extent. Most of the 




334 MANUAL OF VEGETABLE-GARDEN INSECTS 

injury to the young plants may be avoided by dipping them 
before transplanting in arsenate of lead (paste), 1 pound in 
10 gallons of water. Dipping is much more effective than 
spraying the plants because both sides of the leaves are covered 
with the poison. Flea-beetle injury may also be avoided, in 
large measure, by late planting. 

Reference 
N. J. Agr. Exp. Sta. Rept. for 1908, pp. 343-348. 

The Desert Corn Flea-Beetle 

Chcetocnema ectypa Horn 

In the semi-arid regions of the Southwest, beans are some- 
times seriously injured by this small, shining black flea-beetle, 
a little less than y^ inch in length. Its food plants are grasses, 
grains and corn but it occasionally attacks cantaloupes and 
sugar-beets. The beetles appear in the field about the middle 
of February and begin egg-laying in about a month. The 
minute, bean-shaped, whitish eggs, about ,^5^ inch in length, are 
deposited at or near the surface of the ground on or near the 
food plant. The eggs hatch in three to fifteen days with an 
average of five or six. The larvae feed on the roots, often caus- 
ing considerable damage to the roots of alfalfa, barley, oats, 
wheat and corn. They become full-grown in a little over three 
weeks. The mature larva is whitish, elongate, slender, and 
from T to ^ inch in length. When mature, the larva constructs 
an oblong, earthen cell within which it transforms to a shorter 
thickened form known as the prepupa and a few days later to 
a delicate, soft, whitish pupa. The pupal period varies from 
three to twelve days w^ith an average of about six. There are 
three generations annually and in some years a partial fourth 
may develop. The beetles go into hibernation in November 
under rubbish and clumps of grass in waste places. 



FLEA-BEETLES 



335 



Reference 
U. S. Dept. Agr. Bull. 430. 1917. 



The Hop Flea-Beetle 

Psylliodes 'punctulala Melslieimer 



Although this flea-beetle is best 
enemy of hops in the Northwest, 



known as a destructive 
it is widely distributed 
throughout the northern United States and southern Canada 
from the Atlantic to the Pacific and also attacks several garden 
plants, including beet, rhubarb, potato, tomato, turnip, radish, 
cabbage, cucumber, watermelon, mustard and clover. Its 
wild food plants are numerous, including 
hedge mustard, lamb's quarters, pigweed, 
dock, sorrel, tumbleweed and nettle. 

The hop flea-beetle is about ^ inch in 
length and bronzy black in color. The 
antennae are brownish, pale at the base. 
The legs are reddish yellow with the middle 
and front femora black and the hind pair 
bronzy (Fig. 212). The beetles hibernate 
under any convenient shelter, such as cracks 
and crevices of posts or poles, in the hollow 
stems of plants, under grass or weeds, and in the soil itself. 
In British Columbia they emerge in INIarch or April and soon 
begin feeding on the foliage of their food plants, eating out 
pits, but usually do not perforate the leaf. The injured area 
soon dries, however, and may break away, leaving a hole 
through the leaf. The foliage is often riddled in this way and 
in the case of hops the leaves are reduced to mere shreds. 

The females enter the soil to lay their eggs on the roots of 
the hop. The egg is about ts inch long, elliptico-cylindrical, 
and yellowish in color. They are found at a depth of one to 




Fig. 212. —The hop 
flea-beetle (X 10). 



S^Q MANUAL OF VEGETABLE-GARDEN INSECTS 

two inches in the soil. The eggs hatch in about three weeks 
oi a little less, depending on the temperature, and the young 
larva begins feeding on the roots. Although the larvne have 
only been found on hop roots, they undoubtedly feed on other 
plants. They become full-grown in about three weeks. They 
are then about j inch in length, white, with the head, thoracic 
shield and anal plate darker. After reaching maturity, the 
larva becomes somewhat shorter and thicker and rests in a 
dormant condition for nearly two weeks before transforming 
to the white pupa. Pupation takes place in the soil but not 
in an earthen cell. The pupal period averages about sixteen 
days. There are two generations annually. From eggs de- 
posited in the early spring by over-wintered beetles, a new 
brood of adults is produced the last of May or early in June, 
and another brood appears the last of July or the first of August. 
The latter go into hibernation with the advent of cool weather. 

References 

U. S. Bur. Ent. Bull. 66, pp. 71-92. 1909. 
U. S. Bur. Ent. Bull. 82, pp. 33-58. 1910. 

Means of Controlling Flea-Beetles 

It is usually difficult to prevent injury by flea-beetles because 
the attack is made by the adults, most of which feed only 
slightly on the surface of the leaf and are more or less resistant 
to poisons. They also avoid the poison and attack the leaves 
where the spray has not been applied. The attack is usually 
most severe on young plants early in the season when the 
beetles are most voracious after their long winter's fast and 
when the plants are least able to withstand injury. Contact 
insecticides have been found of little value because of the 
difficulty of hitting the insects, since the beetles jump from the 
plants at the slightest alarm only to return when the danger 



FLEA-BEETLES 337 

is passed. Bordeaux mixture has been found the most efficient 
and inexpensive deterrent for most flea-beetles. The presence 
of this material on the leaves makes them distasteful to the 
beetles. When combined with paris green, 2 pounds in 100 
gallons, or arsenate of lead (paste) at the rate of 4 or 5 pounds 
to 100 ■ gallons, it makes the most effective treatment. As 
bordeaux mixture is used on many plants for the prevention of 
fungous diseases, its use serves a double purpose. In some 
cases in which the plants are started in seed-beds and then trans- 
planted into the field, dipping the plants in arsenate of lead 
(paste), 1 pound in 10 gallons of water, before setting has been 
found the most effective way of protecting from fiea-beetle 
attack. When the injury is done to the plants in the seed-bed, 
it is sometimes found advisable to screen the beds with cheese- 
cloth or tobacco-cloth as described under the cabbage root- 
maggot on page 35. Special methods of treatment applicable 
to certain species will be found in the account of these forms. 



CHAPTER XVIII 

UNCLASSIFIED PESTS 

Some of the insects and insect-like animals are so miscel- 
laneous in their feeding that they cannot be associated clearly 
with any one crop. A few of these are treated together here. 
Some of them are very troublesome and are difficult to combat. 

The Root-Knot Nematode 

Heterodera radicicola Greef 

A great variety of plants is subject to serious injury from 
the attacks of minute nearly transparent worms that bore into 
the roots, causing gall-like knots or outgrowths to develop. 
In England these are known as eel-worms. The swellings on 
the roots are produced by the plant in its attempt to repair 
the injury caused by the presence of the worm. The normal 
growth of the root tissue is disturbed, with the result that the 
sap-tubes are distorted and unable to carry their load of raw 
plant-food up to the leaves. Badly infested plants take on a 
weak, unhealthy appearance, become stunted and sometimes 
die. 

The root-knot disease is prevalent throughout the tropics, 
sub-tropics and the warmer parts of the temperate zone. In 
the United States it is occasionally found as far north as New 
York, Michigan and Nebraska but is of little importance except 
in the southern states and in central and southern California. 

338 



UNCLASSIFIED PESTS 339 

It is especially troublesome in irrigated districts and in 
greenhouses even in districts where it does not occur in the 
open. 

Different species of i)lants vary greatly in their degree of 
suscej)tihility to the root-knot disease. Among vegetable 
crops those most susceptible to injury are potato, tomato, 
eggplant, celery, beet, carrot, lettuce, pepper, endive, canta- 
loupe, cucumber, watermelon, squash, pumpkin, lentil and 
salsify ; the following also are sometimes seriously attacked : 
asparagus, onion, cauliflower, cabbage, kale, collard, turnip, 
pepper, bean, pea, radish, spinach and sweet potato. In some 
localities potato tubers become badly infestcfl and acquire a 
warty appearance. Infested potatoes are unsuitable for market 
and should never be used for seed. 

The organism that causes the root-knot disease is not an 
insect but a nematode worm. The young are produced inside 
the old gall, from which they escape through cracks or by work- 
ing their way through the tissue. In this stage the worm is 
about T5 inch in length, slender and eel-like in form. The 
young worms can live for several months in moist earth and 
are able to move readily about among the soil particles. When 
one of these worms finds a young and tender rootlet, it breaks 
its way through the tissue by means of a spear-like organ located 
in the mouth and then passes a short distance into the sub- 
stance of the root. The worm then becomes inactive, swells 
up and the female finally assumes a pear-shaped form. The 
male becomes broadly spindle-shaped and then molts but 
remains within the discarded skin. It then assumes a very 
elongate form and becomes coiled in three or four folds within 
its cyst. It finally escapes and, passing through the tissue of 
the root, finds a female with which it mates before she has 
become fully mature. The fully developed encysted females 
are pear-shaped, about 2V inch in length and a little more than 
half as broad and when the gall is broken open appear as little 



340 MANUAL OF VEGETABLE-GARDEN INSECTS 

pearly white globules embedded in the tissue. Each female 
is capable of producing about 500 eggs, which are laid at the 
rate of ten or fifteen a day. The eggs form a mass often as 
large as the female and are surrounded by a gelatinous sub- 
stance. The eggs are ellipsoidal or sometimes kidney-shaped, 
about twice as long as broad and vary greatly in size, being 
from about sis to ^ho inch in length. Sometimes the eggs 
hatch while still within the body of the mother. The female 
begins to lay eggs about twenty-five days after entering the 
root. The winter is passed in the larval stage in the galls and 
in the surrounding soil. 

The galls produced on different species of plants are variable 
in size and shape, but as a rule the amount of enlargement 
depends on the number of worms entering a root near the same 
point. Plants growing in light sandy soil are more subject 
to injury than when on heavy land. The worms cannot sur- 
vive a thorough drying of the soil as is the case with many 
related forms and are killed if the soil remains saturated with 
water for a long time. 

Means of control. 

Vegetables susceptible to the root-knot disease should not 
be planted on land known to be infested. To free fields of the 
root-knot nematode, they should be planted for one or two 
years to some crop not susceptible to the disease and w^hich 
has a sufficiently rank growth to crowd out all weeds that might 
harbor the pest. Certain varieties of cowpeas, particularly 
the Iron, are not susceptible and are sometimes used for this 
purpose. After the cowpeas are harvested, the ground should 
be plowed and sowed to some winter grain such as rye or wheat. 
The next season another crop of cowpeas should be sown to 
be followed again by grain the second winter. Under certain 
conditions velvet beans or Florida beggarweed may be used 
instead of cowpeas. Care should be taken not to allow weeds 



UNCLASSIFIED PESTS 341 

to grow in the field at any time while attempting to eradicate 
the disease, since many of them serve as hosts for the 
worms. 

Where greenhouse soil has become infested by the root- 
knot nematode, it should either be renewed with fresh imin- 
fested soil or may be sterilized with live steam under pressure. 
This is performed by ha^'ing the beds equipped with lines of 
pipe running through the soil in which at intervals are small 
holes about re inch in diameter for the escape of the steam. 
The beds are covered with straw or with some other material 
and the steam is applied until the soil is thoroughly sterilized. 
This may be determined by placing potatoes in the soil near 
the surface and when they are found to be cooked the steam 
may be turned off. Rows of tiles are sometimes used instead 
of pipes, the steam escaping through the joints. 

INIore or less satisfactory results can be obtained in shallow 
beds by applying a weak solution of formaldehyde, 1 part of 
the 40 per cent commercial solution in 100 parts of water, 
using 1 to li gallons for every square yard of surface. 

Recent experiments in Florida indicate that land may be 
freed of root-knot nematodes by the application of com- 
mercial sodium cyanamid at the rate of 1000 to 5000 pounds 
to the acre. This material should be applied dry and then 
worked into the soil. The land should then be irrigated and 
the crop should not be planted until several weeks later de- 
pending on the amount of material used. Sodium cyanamid 
is too expensive for use on large areas but may be employed 
to advantage on seed-beds and on plots under intensive 
cultivation. 

References . 

Ala. Agr. Exp. Sta. Bull. 9. 1889. 

Mass. (Hatch) Agr. Exp. Sta. Bull. 55. 1898. 

U. S. Bur. Plant Ind. Bull. 217. 1911. 



342 MANUAL OF VEGETABLE-GARDEN INSECTS 
The Sugar-Beet Nematode 

Heterodera schachtii Schmidt 

This near relative of the root-knot nematode has been known 
for many years as an important enemy of the sugar-beet in 
Europe and has recently seriously infested sugar-beets in the 
western United States. It also infests other kinds of beets, 
as well as cabbage and related crops. Its life history is similar 
to that of the species last treated, the most important differ- 
ence being that there is a resting stage in which the eggs may 
survive in the soil for at least six years. The sugar-beet nema- 
tode is, therefore, a much more difficult pest to eradicate, 
since to rid land by crop rotation it would be necessary to keep 
it free from all susceptible crops for a period of several years. 

Millipedes 

There are several species of millipedes injurious to sprouting 
seeds, seedlings and root-crops, such as radishes, turnips, 
carrots, parsnips and beets (Fig. 213). They sometimes eat 
out holes in potato tubers and often infest the heads of cabbage, 
cauliflower and lettuce. Seed beans are attacked underground 
and the millipedes may eat off the tender shoots. Sprouting 
corn and peas are injured in a similar way. The millipedes 
often bore into melons, cucumbers, squashes and tomatoes 
where they touch the ground. 

Millipedes are not insects but belong to a closely related 
class of animals. They are elongate, more or less cylindrical 
creatures, having a distinct head and a body consisting of a 
series of similar segments which is not divided into a thorax 
and abdomen. Each segment, excepting the first four, bears 
two pairs of legs. 

It is often stated that the mouth-parts of millipedes are not 
fitted for feeding on healthy plant tissue, but a dissection of 



UNCLASSIFIED PESTS 



343 



these organs has convinced the writers that they are well 
adapted for this purpose. It is true that millipedes prefer 
decayinfi \'egetable matter but it is also well known that they 
will attack healthy roots when their favorite food is not avail- 
able. Under such conditions they select, wherever possible, 
a part that has already been injured by some insect or that is 
affected with some disease. Roots or 
tubers that have been eaten into often be- 
come infected with fungi or bacteria, causing 
decay. 

Numerous species of millipedes, belonging 
to several genera have been found injurious 
in America but their life history and habits 
do not appear to have been carefully 
studied. 

The greenhouse millipede, Orfhoiiiorpha 
(jracUis Koch, is of tropical origin and is 
common in greenhouses in pAirope and 
America. In this form the body is some- 
what flattened and the segmentation is 
very distinct. On the side of each seg- 
ment is a thin horizontal plate which in 
the posterior segments is acutely pointed 
behind. The full-grown millipede is nearly an inch in 
length, chestnut-brown above, with the lateral plates 
yellowish. 

The commonest millipedes that are injurious in the field 
belong to Julus and related genera. These forms are elongate, 
cylindrical and usually piceous in color with the legs and under 
parts pale. When at rest they are usually coiled in a circle. 
Reproduction is by means of eggs, which the female deposits 
in a mass covered with pellets of earth glued together to form 
an egg-cocoon. The eggs are laid in the spring and again in 
the fall and hatch in about two weeks. The young differ from 




Fig. 213. — a car- 
rot injured by 
slugs and milli- 
pedes. 



344 MANUAL OF VEGETABLE-GARDEN INSECTS 



the adults in size and in ha\'ing a smaller number of body 
segments and fewer legs. 

In New York a common and troublesome species is Julus 
cceruleocinctus Wood. It is nearly an inch in length and has 

been found in- 
jurious to peas, 
beans, tomatoes, 
melons and many 
other vegetables 
(Fig. 214). 

No satisfactory 
method for the 
control of milli- 
pedes under field 
or garden condi- 
tions has been 
devised. In the 
garden they may 
be trapped under pieces of boards or slices of vegetables 
laid on the ground. In the greenhouse they may be trapped 
in the same way or by using lumps of dough sweetened with 
molasses. Lime or tobacco dust applied around the plants 
will have a tendency to keep the pest away. 




Fig. 214. — A millipede, Julus cceruleocinctus (X 5). 



White Grubs 

Lachnosierna (several species) 

Vegetable crops are often seriously injured by large white 
curved grubs that are found in land that has recently been in 
sod. These grubs (Fig. 215) are the larval form of the large 
brown June beetles or June bugs (Fig. 216) that come blundering 
around lights on summer evenings. In the United States 
there are nearly one hundred species, but the greater part of 
the injury is caused by a relatively small number. 



UNCLASSIFIED PESTS 



345 




Fig. 215. — A wliito grub 
(X U). 



The parent beetles are most abundant in May and June. 
They feed at night on the leaves of various trees, but at day- 
break they desert these and return to the fields. The females 
burrow into the soil to a depth of two 
or three inches and there deposit their 
eggs singly or in small groups. Each 
female is capable of laying from fifty 
to one hundred eggs. The eggs are 
oval, white, and have a diameter of 
about T2 inch. They lie in small cells 
composed of soil particles glued to- 
gether with a sticky substance secreted 
by the beetle. The eggs hatch in ten 
days to several weeks. The young grubs feed throughout the re- 
mainder of that season on the roots of grasses a short distance 
below the surface of the ground. With the approach of cold 
weather, they burrow deeper into the soil .and hibernate at a 
depth of ten or twelve inches. The following spring they re- 
turn to the grass roots, on 
which they feed through- 
out the season. The 
grubs of some species 
reach maturity at the 
end of the second sum- 
mer, but in the case of 
our more common species 
the grubs are not full- 
grown at that time. In 
the latter case, the grubs 
again descend into the 
soil for hibernation and 
return to the grass roots in the spring of the third year. After 
feeding for a period, they become full-grown in June or July. 
The grub then constructs an oval earthen cocoon in which it 




Fig. 216. — Two specie.s of June beetles, 
the adults of the white grub Lachnosterna 
ilicis and L. hirtioila. 



,346 MANUAL OF VEGETABLE-GARDEN INSECTS 

transforms to a delicate whitish pupa. The insect remains in 
this condition until the latter part of the summer and then 
transforms into a jpeetle. It remains in the earthen cell until 
the following spring, when it emerges from the ground. While 
certain species emerge the second spring after the eggs are 
laid, and a few do not emerge until the fourth spring, the 
greater number of the injurious species do not emerge until 
the third spring. For instance, in the last case the young 
grubs that hatch from eggs laid in the spring of 1918 feed until 
the fall of that year, hibernate during the winter of 1918-19, 
feed again through the summer of 1919, hibernate again as 
grubs during the winter of 1919-20, complete their growth, 
pupate, and transform to beetles that season and hibernate 
as beetles during the winter of 1920-21 ; the beetles emerge 
in the spring of 1921. It will be seen from the foregoing ac- 
count that the grubs are most destructive during the second 
season, because it is then that they feed for the longest period 
and make their greatest growth. The first year the grubs 
feed only during the latter part of the season and are very small. 
The third summer they feed only during the early part of the 
season and only enough to prepare themselves for pupation. 

In case infested sod land is broken up and planted to vege- 
table crops, the white grubs are forced to concentrate their 
feeding on the latter. Corn, potato, beet and other root crops 
are especially liable to attack ; in fact, there is scarcely a vege- 
table crop that is not subject to injury when grown on infested 
land. 

Crops liable to injury by white grubs should not be planted 
on land known to be infested. Much trouble may be avoided 
by adopting a short rotation of crops in which land will not be 
left in sod for more than two or three years. White grubs are 
likely to be abundant in old strawberry beds and when these 
are plowed up they should be treated the same as sod land. 
Buckwheat, alfalfa, clover and other leguminous crops are not 



UNCLASSIFIED PESTS 347 

relished by white ^riibs and may be used as intermediate crops 
between sod and ve,<i;etables. As previously stated, the f:;rubs 
do the greatest injury during the season following that in whieli 
the eggs are laid. Observations in Illinois have shown that the 
beetles prefer to lay their eggs in ground that is well covered 
with vegetation. Pasture land, wheat, and oats are chosen 
in the order named. Clover is a relatively immune crop, 
very few eggs being laid in fields where there is a heavy stand. 
These facts should be kept in mind when planning a rotation 
of which vegetable crops are a part. 

In some parts of the country, white grubs appear in more or 
less definite broods and are destructive in three-year cycles. 
In localities where this tendency is well developed, this knowl- 
edge may be utilized to avoid injury. 

WiREWORMS f 

Several Species of Elateridce 

Many vegetable crops are liable to attack by wireworms es- 
pecially when planted on land previously in sod. Wireworms 
(Fig. 217) are elongate, hard- 
shelled, brownish larvae, the im- 
mature stages of medium-sized, 
dull-colored, snapping beetles or 
click-beetles. Thev are under- ,, „ . . 

*" rT> 1 vui. '2\i. — A wireworm, Mono-- 

ground msects that eat off the crejMius Uvidus {x il). 

smaller roots, bore into tubers 

and fleshy roots and destroy germinating seed. The beetles 
appear in ]\Iay and June, and the females deposit their eggs 
in the soil. The beetles are from i to |^ inch in length, dull 
grayish brown in color, and have the peculiar habit of snap- 
ping themselves into the air when laid on their backs. The 
larvae feed on the grass roots for several seasons, the various 
species differing in the length of their life cycle from three to 




348 MANUAL OF VEGETABLE-GARDEN INSECTS 




Fig. 218. — A potato infested 
with wheat wireworms. 



six years. The wireworms reach maturity early in July. 
They are then from ^ to 1^ inches in length, depending on 

the species. They transform to 
delicate whitish pupse in earthen 
cells within six inches of the 
surface of the ground. Trans- 
formation to the beetle takes 
^V place in three weeks to a month, 
■%5 the beetles remaining within 
'^ the earthen cell until the follow- 
ing spring. There are many 
species of wireworms that may 
attack vegetables but only the 
most important can be treated 
here. 

The wheat wireworm, Agriotes 
maiwus Say, is about an inch in length when full-grown, pale 
yellow in color, cylindrical in form and may be recognized by 
the two dark spots at the base of the 
last segment of the body. This species 
feeds normally on the roots of grasses / 
but when the sod is broken up will 

seriously injure corn, \t 
wheat, potato, car- s 
rot, turnip, bean, 
cucumber and cab- 
bage. Injured po- 
tatoes are shown in 
Figs. 218 to 220. 

The adult of the wheat wireworm is 
about ^ inch in length, dull reddish brown, 
Fig. 220. — The same darker on the head and thorax. The 
potato cut open to bg^tlcs are to be found in the field from 

show the burrows 

made by wireworms. April to June. The female enters the 





Fig. 219. — Potato injured 
by the wheat wireworm. 



UNCLASSIFIED PESTS 349 

ground to deposit her eggs. The larvae become about half- 
grown by the end of the season ; they resume feeding the 
following spring and become nearly full-grown by the second 
winter. They reach maturity in July of the third summer 
and construct earthen cells in which they transform to small 
whitish pupse and a little later change to beetles. The beetles 
do not emerge the same season but remain in the pupal cells 
till the following spring. Three years are required for the 
completion of the life cycle. 

The corn wireworm, Melanotiis communis Gyllenhal, is 1^ 
inches in length when full-grown, cylindrical, reddish brown in 
color and the last segment of the body is provided with three 
lobes. The beetle is about ^ inch in length and of a dull red- 
dish brown color. In this form the life cycle may require six 
years for its completion. Corn wireworms are most trouble- 
some on heavy, poorly drained soils. 

The sugar-beet wireworm, Limonius californicus Manneheim, 
has been reported as injurious to sugar-beet, lima bean, po- 
tato, corn and alfalfa in California. The beetle is a little less 
than I inch in length, and brown to dusky black in color. 
The adults appear in the field in early spring and after re- 
maining in a sluggish condition for some time the females 
burrow into the ground to deposit their eggs. Most of the 
eggs are laid between the middle of April and the middle of 
May and hatch in a little less than a month. Three years are 
spent in the larval state. The full-grown wireworm is about 
f inch in length and shiny, waxy, yellowish broAvn in color. 

The confused wireworm, Limonius confusus Leconte, has 
been recorded as attacking potato, tomato, onion, cabbage, 
radish, horse-radish and corn in Illinois. A related species, 
Limonius agonus Say, is treated as a tomato pest on page 173. 

The corn and cotton wireworm, Horistonotus uhlerii Horn, 
is sometimes injurious in the South to corn, oats, rye, cowpeas, 
peanuts, cotton, tobacco, sweet potatoes and watermelons. 



350 MANUAL OF VEGEr ABLE-GARDEN INSECTS 

This species is an exception to the general rule and is most 
destructive on light sandy soil in the higher parts of fields. 
The beetle is -g^ to ^ inch in length and brownish red in color. 
The larva is very slender, soft and has the body apparently 
composed of twenty-six segments. 

Co7itroI. 

Wireworm injury to vegetable crops can be prevented in 
large measure by practicing a short rotation of crops in which 
the land is not left in grass for more than two, or at most, three 
years. Peas and buckwheat are relatively immune to wire- 
worm attack and may sometimes be used to advantage between 
sod and corn or other susceptible crops. Deep and thorough 
cultivation of the soil in late July and August will break open 
the pupal cells and destroy the pupae and recently transformed 
adults, thus reducing the number of beetles the following 
spring. Late fall-plowing is of little value in destroying 
wireworms. 

In the garden poisoned baits are sometimes used for killing 
the wireworms as well as the beetles. Small bunches of clover 
or other succulent plants are dipped into paris green water 
and then placed in the field covered with earth or pieces of 
boards. Sweetened corn-meal dough poisoned with paris green 
or other arsenical may be used instead of the clover. These 
baits should be distributed after the ground has been fitted but 
before the crop is planted and should be kept fresh by frequent 
renewals. 

Grasshoppers 

Nearly all vegetable crops are subject to injury by various 
species of grasshoppers when grown in localities where these 
insects are abundant. Grasshoppers are most likely to be 
destructive in regions where the soil is sandy and where there 
are large areas of waste land, because it is in such situations 



UNCLASSIFIED PESTS 851 

that tlicy find ('oiiditioiis most suitable for depositing tlieir 
eggs. 

An effective and practicable method of destroying grasshop- 
pers is by the use of a poisoned bait made according to the 
formuhi given on page 299. 

The Red-Spider 

Tetranychus telarius Linnaeus 

It has often been pointed out that the common name of this 
pest is inappropriate because it is neither a spider nor is it al- 
ways red, but as this name has been in use for many years it 
would seem unwise to designate it as the spider mite as has 
been suggested recently. The red-spider is a mite belonging 
to the class Arachnida. On hatching, this mite is provided 
with three pairs of legs but before reaching maturity acquires 
a fourth pair. The mouth-parts are adapted for piercing the 
epidermis of the leaf on the juices of which the animal feeds. 
The red-spider attacks a great variety of plants both in the 
greenhouse and in the open. Of the former, roses, chrysan- 
themums, violets and carnations are particularly liable to in- 
jury while of the latter, arbor-vitse, juniper, lilac, snowball and 
red sage should be mentioned. In the nursery some cherries 
may be attacked. The red-spider is also an important enemy 
of cotton and sometimes becomes troublesome on okra, cu- 
cumber, melon, eggplant, bean, tomato, pepper, sugar-beet, 
hops and orchard trees. Bramble fruits are especially liable 
to attack. The red-spider is almost cosmopolitan in its dis- 
tribution, occurring wherever suitable food plants are found 
and being most abundant in those regions where the climate is 
dry. The mite is usually most troublesome in seasons of 
drought or in greenhouses where the moisture is deficient. 

The full-grown female red-spider (Fig. 221) is a little less 
than -^jj inch in length ; the male measures about yV inch. 



352 MANUAL OF VEGETABLE-GARDEN INSECTS 



The mite varies greatly in color from greenish through yel- 
lowish to orange or reddish ; some are brownish. Usually 
the body is marked with one to three pairs of black spots. In 
some cases the spots are confluent and the mite appears black. 
The eyes are red. The legs are pale and in the male the two 
front pairs are usually tinged with reddish. Seen from above 
the mite's body is broadly ovate in out- 
line. It is not divided into three regions 
as in insects. The mouth-parts consist 
of a pair . of sharp needle-like protrusile 
bristles and a pair of shorter fixed spines. 
In feeding the mite pierces the epidermis 
of the leaf with its mouth-parts and 
through the puncture extracts the juices 
of the plant. This mite covers its feed- 
ing grounds with a maze of delicate 
silken threads. The silk is produced by 
glands opening near the tip of the body. 
The claws at the tip of the legs are 
especially adapted to enable the mite to 
travel over the web. 

The female deposits her spherical, pearly 
white eggs, about 2To' ^^ch in diameter, 
singly on the underside of the leaves, to 
which they are usually attached by strands 
of silk. As the eggs develop they take on a reddish hue and 
the eyes of the embryo become evident as small red spots. 
Each female is capable of laying from 50 to 100 eggs over a 
period of nearly a month. The eggs hatch in three to eight 
days. On hatching the young mite is provided with only 
three pairs of legs ; it is about y^s »^ch in length and the 
body is nearly spherical in outline when viewed from above. 
The young mite soon begins feeding near the egg-shell and 
in about three days molts its skin. In the second stage 




Fig. 221. — The red- 
spider ( X 66). 



UNCLASSIFIED PESTS 353 

the mite is provickni with four pairs of legs ; it is nearly 
aV int'h in length. It feeds actively and in about three 
days molts again. The third stage nymph averages -jq inch in 
length. In this stage the mite develops the habit of spinning 
a web. In about three days the mite molts for the third and 
last time and assumes the adult condition. It is thus seen that 
in the course of its development the mite passes through three 
immature stages and reaches maturity in nine or ten days after 
hatching from the egg. In about three days the females 
begin egg-laying. The number of generations produced an- 
nually varies with the length of the season and with the con- 
dition of temperature and moisture. When the weather is 
dry and hot the time elapsing from the laying of the egg to the 
time at which the mature female lays her first egg may be only 
nine or ten days, but in the cooler weather of the spring and 
autumn this period may be lengthened to over a month. Ob- 
servations of the mite on cotton in South Carolina have shown 
that breeding from the first egg laid by the females of each 
generation as many as seventeen generations may be produced 
annually but owing to the fact that the mites may continue 
egg-laying for a month or more several of the later generations 
must be only partial. I'^nder greenhouse conditions breeding 
may be continuous throughout the year. 

The injury caused to most plants by the red-spider is indi- 
cated by small light-colored spots on the leaves, the result of 
the death of the plant cells around the feeding punctures. When 
numerous these spots coalesce and the leaves take on a whitish 
appearance. Injured plants usually become paler or take on a 
reddish cast and finally the leaves may shrivel and die. 

Control. 

In the greenhouse the red-spider may be held in check by 
watering the plants frequently with a nozzle that gives a stiff 
SI ray without delivering enough water to drench the beds. 

2 A 



354 MANUAL OF VEGETABLE-GARDEN INSECTS 

Liberal watering of plants in the open will also have a beneficial 
effect on preventing red-spider injury. "Black Leaf 40" to- 
bacco extract, 1 part in 1000 parts of water in which soap has 
been dissolved at the rate of i pound to 5 gallons will also be 
found useful in freeing the plants of the pests. The tobacco 
extract is also effective when combined with the oil emulsions 
or with bordeaux mixture. The mites may also be held in 
check by dusting the plants with finely ground sulfur. 

Reference 
Ore. Agr. Exp. Sta. Bull. 121. 1914. 

Slugs 

Slugs are closely related to snails, from which they differ in 
having the shell reduced to a thin plate or wanting altogether. 
The commonest species injurious to vegetables in the eastern 
LTnited States is the gray field slug, Agriolimax agrestis Linnaeus 

(Fig. 222) and has appar- 
ently been introduced from 
Europe. It is about It 
inches in length when fully 
Fi J. 222. — The gray field slug ( X U). extended, spindle-sliaped in 

outline, ashy gray in color 
mottled with darker gray. On the head are two pairs of 
fleshy tentacles ; the upper pair is the longer and bears 
the eyes at the tip. When at rest or when disturbed the 
tentacles are withdrawn and the body contracts into a dull 
gray lump. Slugs are found in cool, moist situations. During 
the day they are hidden away under stones or boards and 
come out to feed only at night or on damp cloudy days. 
Their bodies are kept moist by a slimy secretion a trail 
of which is left behind wherever they go. These glistening 
snail tracks are often seen on boards left lying on the ground. 




UNCLASSIFIED PESTS 



355 




Fig. 223. — A cluster of eggs of the gray 
field slug ( X 3). 



When irritated as by an 

application of lime, they 

throw out a copious quan- 
tity of this protective 

secretion. The slug's 

mouth is provided with a 

tongue-like organ thickly 

studded with minute sharp 

teeth by which the animal 

is able to rasp off tender 

plant tissue. Slugs are 

hermaphroditic, both male 

and female organs being present in the same individual. The 

eggs are deposited from spring till late fall in loose clusters of 

thirty or forty in moist 
ground, under stones or 
other shelter. The eggs 
(Fig. 223) are nearly 
spherical, translucent and 
about T2 inch in diameter. 
They hatch in three to ten 
weeks depending on the 
weather. If dried they 
shrink considerably but 
regain their size when 
moistened. The time re- 
quired for a slug to reach 
maturity depends on condi- 
tions of moisture and food 
and varies from six weeks 
to nearly a year. They are 
said to live for several years. 
^ ,,. , , , . . , Slugs are most trouble- 

beedhng bean plants injured . p ■> 

by slugs. some m seasons or abun- 




FiG. 224. 



356 MANUAL OF VEGETABLE-GARDEN INSECTS 




Fig. 225. — Base of a cabbage leaf riddled by slugs. 



dant moisture and on heavy soil that does not dry out quickly. 
They sometimes eat out holes in potato tubers and in the roots 
of radishes and carrots (Fig. 213). Corn and tobacco seedlings 

are sometimes destroyed and they 
may cause serious injury to bean 
plants (Fig. 224) by eating into 
wP ^m.' the stems, devouring the buds and 

riddling the leaves with holes. 
They may also bore into the un- 
ripe pods. The leaves of celery, 
lettuce, cabbage, cauliflower, radish 
„ „„„ , , , . and the sprouts of potatoes are 

Fig. 226. — A sreon tomato in- ^ , r»ne\ 

jured by slugs. frequently attacked (Fig. 225). 




UNCLASSIFIED PESTS 357 

Slugs often bore into ripening tomatoes but sometimes attack 
them while still green (Fig. 226) and are often found resting 
in cavities eaten out in ripening strawberries. 

A smaller, nearly black species, Agriolimax campestris Bin- 
ney, is often associated with the gray field slug. It closely 
resembles that form in habits and inflicts similar injuries. 

Control. 

Slugs may be killed by using the poison bait recommended 
for the control of cutworms on page 299, or by poisoning sliced 
potatoes with paris green or other arsenicals. Dusting the 
plants and the surrounding ground with air-slaked lime or land 
I)laster will have a tendency to kecj) them away. Bordeaux 
mixture also has a deterrent efi'ect and on some crops may be 
used to advantage. In some cases the plants may be sprayed 
with arsenate of lead either alone or in combination with 
bordeaux mixture. 



The Yellow Bear Caterpillar 

Diacrisia virginica Fabrieius 

Many vegetables are occasionally subject to attack by large 
hairy caterpillars which from their shaggy appearance and 
clumsy gait have received the suggestive names of yellow and 
woolly bears. The yellow bear is widely distributed from 
Nova Scotia to California southward to Mexico and Cuba. 
The caterpillars are very general feeders attacking asparagus, 
bean, pea, beet, salsify, cabbage, cauliflower, radish, turnip, 
carrot, celery, eggplant, onion, parsnip, corn, peanut, canta- 
loupe, pumpkin, squash, potato, rhubarb, sweet potato, water- 
melon, grasses, alfalfa, grape, currant, gooseberry, raspberry, 
canna, dahlia, hollyhock, hyacinth, morning-glory and various 
other plants. 



358 MANUAL OF VEGETABLE-GARDEN INSECTS 

Hibernation takes place in the pupal state and the moths 
emerge from early spring to June. The moths have an expanse 
of 1-^ to 2 inches. The wings are pure white ; the front wings 
marked with a small black dot near the center ; the hind wings 
usually with three black dots. The head and thorax are clothed 
with white down ; the abdomen is white with two orange 
bands and three rows of black spots. The eggs are deposited 
in clusters of fifty to sixty or more on leaves. The egg is 
spherical, about -^^ inch in diameter and shining white to golden 
yellow in color. The eggs hatch in seven days. The young cater- 
pillars feed at first in colonies on the underside of the leaves, 
skeletonizing them, but later scatter and riddle the leaves, 
leaving only the ribs. They become mature in about four 
weeks. The full-grown caterpillar is from 1|^ to 2 inches in 
length, covered with fine soft hairs intermingled with larger 
one's and varying from pale yellow to deep reddish brown, 
shading to blackish in front. They then leave their food plants 
and seek shelter under the loose bark of trees, under boards 
or similar situations, where they construct cocoons mostly com- 
posed of hairs from their bodies fastened together with a few 
threads of silk. The reddish brown pupa is about f inch in 
length. The pupal period lasts from one to two weeks. In 
the northern United States there are two broods annually. 

Control. 

The larger caterpillars feed in exposed situations and are 
readily controlled by hand-picking. The smaller ones are 
easily poisoned by spraying with arsenate of lead (paste), 2^ 
pounds in 50 gallons of water. 



References 

Riley, 3rd Rept. Ins. Mo., pp. G8-69. 1871. 
Dickerson, Moths and Butterflies, pp. 192-195. 1901. 



UNCLASSIFIED PESTS 359 

The Salt-Marsh Caterpillar 

Esligmene acrcva Drury 

Nearly a century ago, T. W. Harris made a careful study of 
the life history and habits of this insect, which he named the 
salt-marsh caterpillar because of its injuries to hay grown on 
the salt marshes of the Massachusetts coast. This name has 
been retained though somewhat misleading, as the caterpillars 
are not confined to salt marshes but also feed on a great variety 
of grasses and garden crops including cabbage, beans and peas. 
The insect is distributed throughout North America from 
Hudson Bay to Central America. 

Hibernation takes place in the pupal stage and the moths 
emerge in late May and June. The moth has an expanse of 
If to 2^ inches. In the female the wings are white and marked 
with numerous small black spots. In the male the hind wings 
anrl under surface are yellow and spotted as in the female. 
The abdomen above is orange with three rows of black spots ; 
the tip is white. The yellow, nearly spherical eggs, about -^^ 
inch in diameter, are laid in patches about the middle of June, 
a single female laying as many as 1200 eggs. The eggs hatch 
in about a week and the young caterpillars feed at first in 
colonies but soon scatter. They reach maturity in about 
seven weeks, that is, about the middle of August. The cater- 
pillar is then about If inches in length and covered with long 
mouse- and fox-colored hairs arising from large tubercles, 
twelve tubercles to a segment. The nearly mature caterpillars 
are often seen wandering about in search of food or places in 
which to pupate. The cocoons are hidden away in any sheltered 
place and are largely composed of the caterpillar's hairs inter- 
woven with silk and lined with a layer of silk. The pupal 
period in the summer lasts from two to three weeks. In New 
England there are twt) generatit)ns annually. 



360 MANUAL OF VEGETABLE-GARDEN INSECTS 

This caterpillar may be controlled by the same measures as 
suggested for the preceding species. 

Reference 
Harris, Mass. Agr. Rept. and Jour. 7, pp. 322-333. 1823. 



CHAPTER XIX 
INSECTS AND INSECTICIDES 

In order successfully to prevent insect injury to any crop, 
it is necessary to take into consideration various factors, as 
for instance : the life history of the insect ; its habits and struc- 
ture in its various stages ; the method and rate of reproduc- 
tion ; how, when and on what part of the plant it feeds, both 
in its immature and adult condition ; where and in what stage 
it passes the winter ; and its susceptibility to the action of 
poisons and contact insecticides, as well as the eflfect of these 
substances on the plant concerned. In order to devise a 
practical means of control, it is also necessary to take into 
consideration the conditions under which the plant is grown, 
the methods of propagation, cultivation and harvesting as 
well as the commercial value of the crop. 

In the preceding chapters, an attempt has been made to 
give the more important facts known touching on these points. 
In the present chapter are presented some general considera- 
tions in regard to the structure and development of insects 
that are of interest from the standpoint of control, followed 
by a discussion of the more important insecticides used against 
vegetable insects. 

Structure of Insects 

Insects possess an external skeleton or shell composed of a 
series of segments or rings which is divided into three well- 

361 



362 MANUAL OF VEGETABLE-GARDEN INSECTS 

defined regions, — head, thorax and abdomen (Fig. 227). The 
head bears a pair of antennte, a pair of compound eyes and often 
three simple eyes or ocelH. On the thorax are borne three pairs 
of legs and in the adult condition two pairs of wings, except 



AntenTia Sucking Be&k. 



Head 



Thorax-* 



Abdomen"* 




-Fore Wing 



^Hind Wing 



31^ Leg 



Fig. 227. — Ventral view of a squash-bug. 



in the flies, when the hind pair is represented by a pair of knobbed 
appendages known as poisers. The legs (Fig. 228) consist of a 
series of segments named as follows, beginning with the one 
nearest the body : coxa, trochanter, femur, tibia and tarsal 
joints. 



INSECTS AND INSECTICIDES 



363 



Coxa 

TrochoLnter- 

Pemur- 



The wings are modified in varions ways; in the butterflies 
and moths they are usually covered with scales ; in the beetles 
the front wings are hard and horny and are known as wing- 
covers under which the hind wings 
are folded when in repose. In many 
true bugs the front wings are of a 
leathery texture except the tip, which 
is membranous. 

In the female the abdomen is often 
provided with a sharp ovipositor by 
means of which she is able to insert 
her eggs into the tissue of plants. 

IIow bisects feed. 

The mouth-parts of insects are 
adapted for feeding in various ways 
and on all kinds of plant tissue. In 
order to make intelligent efforts to 
control insects, it is necessary to 
know exactly in what way they take 
their food. For purposes of control, 
insects may be roughly divided into 
three classes as follows : 

1. Chewing insects: In this grouj) 
the mouth is provided with a pair 
of hard horny jaws or mandibles 
(Fig. 229) with which the insect is 
able to bite off portions of plant 
tissue, which are then swallowed. 
Beetles and caterpillars belong to 
this class. It is usually possible to 
kill such insects by poisoning their 
food. Arsenic in some form is 
generally employed for this purpose. 



Tibia- 



Tarsus 




Fig. 228. 



• Leg of a blister- 
beeUe. 



364 MANUAL OF VEGETABLE-GARDEN INSECTS 



2. Sucking insects: This term is usually applied to insects 
which have the mouth-parts modified to form a beak con- 
taining four bristles united into a slender tube with which 
they puncture the tissues of the plant and suck out the juices 

(Fig. 230). Plant-lice and 
other true bugs possess this 
type of mouth-parts and are 
controlled by the use of con- 
tact insecticides. 

3. Lapping insects : In 
some flies the mouth-parts 
are developed into a tongue- 
like organ with which they 
are able to lap or lick up 
liquids but which is not fitted 
for piercing plant tissue (Fig. 
231). Sweetened arsenical 
baits have been used success- 
fully for the control of some 
insects belonging to this class. 

IIow insects breathe. 

Insects breathe through a 
series of openings called 
spiracles extending along the 
side of the body. These open- 
ings connect with tubes called 
tracheae which, subdividing 
again and again, extend to all parts of the body. Some 
contact insecticides, such as soaps, are supposed to clog the 
spiracles and kill the insect by suffocation ; others, like the 
oils, are said to penetrate the thin walls of the tracheae and 
thus reach a vital part ; and it is thought that the fumes of 
nicotine arising from the spray applied to the insect are 




Fig. 229. — A grasshopper feeding, 
showing the biting type of mouth- 
parts. 



INSECTS AND INSECTICIDES 



365 



carried through the tracheae to the nervous system where 
they cause death by paralysis. 




Fig. 230. 



A tarnished plant-bug feeding, showing the sucking type of 
mouth-parts. 



The development of insects. 

]\Iost insects, with the exception of some scale insects and 
certain forms of plant-lice, reproduce by means of eggs. The 
newly hatched insect usually 
bears little resemblance to the 
adult. As it increases in size, 
its skin becomes too small, a 
new skin is formed beneath the 
old one and the latter is dis- 
carded ; this is known as molt- 
ing. The period between two 
successive molts is called an 
instar. The number of instars 
varies in different insects from Fig. 23 1. — Head of the onion mag- 




got fly, showing the lapping type 
of mouth-parts. 



three to six or seven ; five is the 

more common number. In some 

insects the change from the immature condition to the winged 

adult takes place without any material change in form ; in 



366 MANUAL OF VEGETABLE-GARDEN INSECTS 

others the transformation is abrupt and striking. In the 
former case the insect is said to have an incomplete meta- 
morphosis ; in the latter a complete metamorphosis. 

Incomplete metamorphosis. 

In this type of development, the immature stages resemble 
the adult in form. The wings develop externally as pad-like 
outgrowths of the thorax but do not become functional till 
the adult stage is reached. The immature forms are known 
as nymphs. In this type of development, the life cycle of the 
insect consists of three stages, viz., the egg, the nymph (three to 
five instars) and the adult. The true bugs and grasshoppers 
have incomplete metamorphosis. 

Some authors refer to the early nymphal stages of plant-lice 
as larvfe and to the last nymphal stage, in which the wing-pads 
are present, as pup^e. According to this system in the thrips, 
the first two nymphal stages are called larvae, the third stage 
a prepupa and the fourth a pupa. These terms are somewhat 
confusing and are not followed in the present work. It is 
preferable to restrict the terms larva and pupa to the early 
stages of insects having a complete metamorphosis. The 
various stages of an insect with incomplete metamorphosis 
are shown in Fig. 232. 

Complete metamorphosis. 

In this case the immature stages of the insect bear little or 
no resemblance to the adult. The wings develop internally 
in pockets formed by an infolding of the body-wall of the thorax. 
The immature stages are known as larvae. The larva molts 
five or six times, and when full-grown transforms to an inactive 
pupa, often in a cocoon or earthen cell prepared by the larva. 
The pupa is a resting stage in which the organs of the larva 
are more or less broken down and made over into those of the 
adult. In the pupa, the antennae, legs and wings of the adult 




Pig. 232. — The various stages in the development of Idiocerus scurra, a leaf- 
hopper on poplar, an insect with incomplete metamorphosis. 1 to 5, first 
to fifth nymphal stages ; 0, adult ; 7, egg. (All enlarged but not in the same 
proportion.) 



368 MANUAL OF VEGETABLE-GARDEN INSECTS 

are usually evident, closely applied to the body and covered 
by the pupal skin. When the remarkable internal structural 
changes in the pupa are complete, the adult winged insect 
emerges. In this type of development there are four stages, 
viz., egg, larva (five to six instars), pupa and adult. Butter- 
flies, moths, beetles and flies have complete metamorphosis. 
The four stages of an insect with complete metamorphosis 
are illustrated in Figs. 93 to 97 of the tomato worm. 

The larva? of flies are commonly known as maggots ; those of 
butterflies and moths as caterpillars, and the larvae of beetles 
as grubs. The pupa of a butterfly or moth is often called a 
chrysalis. 

Insecticides 

Injuries to vegetable crops by insects may be prevented by 
various cultural practices, such as clean farming to reduce 
hibernating shelter and to destroy the weeds and other wild 
plants on which injurious species breed, and from which they 
spread to cultivated crops, and by a proper system of rotation 
in which the same crop is not planted on the same land for a 
series of years and in which crops that are attacked by the same 
insects do not succeed each other. In some cases, collecting 
and destroying crop remnants is of great importance in pre- 
venting injury in the same or near-by fields the following year. 
Taken all in all, clean farming in combination with a proper 
crop rotation is the most important and practical method of 
preventing loss from insect attacks to vegetables. 

In the case of some crops, cultural practices can usually 
be relied on to prevent serious insect injury, but with most 
crops recourse must be had to special applications of materials 
that either poison the insects or kill them by coming into con- 
tact with their bodies. Such substances are known as insec- 
ticides. 

Insecticides are usually divided into two classes, internal 



INSECTS AND INSECTICIDES 369 

poisons and those that kill by contact. The former are used 
against chewing insects and kill by being taken into the diges- 
tive tract ; the latter are not eaten but are applied directly 
to the insect's body and produce death in various ways, either 
by suffocation, by corrosive action or by fumes that penetrate 
the breathing pores of the insect. 

Insects infesting stored seeds and tubers may be killed by 
fumigating with poisonous gases. 

Arsenic. 

White arsenic, arsenious oxid (AS2O3), is a white powder. 
It is the cheapest form in which arsenic can be obtained. It 
is soluble in water and therefore very injurious to foliage. 
Sodium arsenite, a cheap and efficient insecticide, may, however, 
be prepared from it by the following method : 

Sal soda 2 pounds 

Water 1 gallon 

Arsenic 1 pound 

Mix the white arsenic into a paste and then add the sal soda 
and water, and boil until dissolved. Add water to replace any 
that has boiled away, so that one gallon of stock solution is 
the result. Use one quart of this stock solution to fifty gallons 
of bordeaux mixture. This material is little used, except for 
potato spraying, and should always be applied in combination 
with bordeaux mixture and even when so used care should be 
taken that there is enough lime in the mixture to neutralize 
the caustic action of the asenic. 

Paris green. 

Pure paris green, 3Cu(As02)2 • Cu(C2H302)2, is composed 
of copper oxid, CuO, acetic acid, HC2H3O2, and arsenious oxid, 
AS2O3, chemically combined as copper-aceto-arsenite as follows: 
2b 



370 MANUAL OF VEGETABLE-GARDEN INSECTS 

Copper oxid 31.29 per cent 

Arsenious oxid 58.65 per cent 

Acetic acid 10.06 per cent 

The commercial grades often contain impurities and vary 
somewhat from the above. By the National Insecticide 
Law of 1910, paris green must contain at least 50 per cent of 
arsenious oxid, and must not contain arsenic in water-soluble 
form equivalent to more than 3^ per cent of arsenious oxid. 

Paris green is most widely used for spraying potatoes and is 
usually combined with bordeaux mixture. When used in 
water, an equal weight of lime should be added to neutralize 
any soluble arsenic present and thus prevent burning of the 
foliage. For many purposes paris green is now largely re- 
placed by arsenate of lead, which is less likely to burn the leaves 
but is a little slower in its effect on the insects. 

Paris green is sometimes applied in the dry form and may 
then be diluted with hydrated lime or land plaster. 

London lyurple. 

London purple is an arsenite of hme obtained as a by-product 
in the manufacture of aniline dyes. Its composition is variable, 
the arsenic content varying from 30 to 50 per cent. It is a finer 
powder than paris green and, therefore, remains longer in sus- 
pension in water. It is used in the same way as paris green, 
but owing to the presence of much soluble arsenic, is likely to 
cause foliage injury. This can be averted by the use of lime as 
advised under paris green. London purple is now little used as 
an insecticide. 

Arsenate of lead. 

Arsenate of lead has practically replaced paris green for 
spraying orchard trees and its use on vegetable crops is rapidly 
becoming more widespread. It contains less soluble arsenic 



INSECTS AND INSECTICIDES 371 

and, therefore, does not have as great a tendency to burn the 
foHage ; it adheres better to the leaves but is a little slower 
in its action on the insects. 

Chemically, arsenate of lead may be either triplumbic arse- 
nate, Pb3(As04)2, or plumbic hydrogen arsenate, PbHAs04. 
The commercial product usually consists of a mixture of these 
two forms, the proportion depending on the method of manu- 
facture employed. The triplumbic arsenate of lead is prepared 
by combining normal sodium arsenate, Xa3As04, with either 
lead acetate, rb(C2H302)2, or lead nitrate, Pb(N03)2. If any 
di-sodium hydrogen arsenate, Xa2HAs04, be present, there is 
then formed some of the plumbic hydrogen arsenate. Arse- 
nate of lead is sold in two forms, a thick paste and a fine powder. 

Under the National Insecticide Act of 1910, arsenate of lead 
paste must not contain more than 50 per cent water and must 
contain the arsenic equivalent of at least 12i per cent arsenic 
oxid, AS2O5. The water-soluble arsenic must not exceed an 
equivalent of f of one per cent of arsenic oxid. Some of the 
commercial preparations contain a larger percentage of arsenic 
than required by the law. In the best grades of arsenate of 
lead paste, the chemical is in a finely divided condition, and 
thus when diluted for use remains in suspension for a consider- 
able time. If the paste contains less than 50 per cent water, 
it is likely to be lumpy and requires considerable time and labor 
to get it into condition for use. 

Powdered arsenate of lead is usually considered to contain 
twice as much arsenic as the paste. It is often stated on theoret- 
ical grounds that powdered arsenate of lead does not adhere 
as well to the foliage as the paste form, but practically there is 
little if any difference. The powder is more convenient to use, 
it mixes more readily with water and broken packages are not 
injured by drying out or by freezing. In the preceding chapters 
the quantity of arsenate of lead to be used has been given in 
terms of the paste form but in most cases the powdered form 



372 MANUAL OF VEGETABLE-GARDEN INSECTS 

may be used with equally good results and only one half the 
quantity is necessary. 

Zinc arsenite. 

Arsenite of zinc, Zn(As02)2, is a light fluffy powder and con- 
tains the equivalent of 40 per cent arsenious oxid. It is some- 
times used as a substitute for arsenate of lead. It has a greater 
tendency to burn the foliage when used in water but is fairly 
safe if combined with bordeaux mixture. It is probable that 
foliage injury by zinc arsenite is due to the solubility of this 
poison in water containing a small quantity of carbonic acid ; 
the latter is usually present on the leaves, being derived from 
the respiration of the plant. One pound of zinc arsenite is 
equivalent in effectiveness to about three pounds of arsenate 
of lead paste. 

Calcium arsenate. 

Commercial calcium arsenate consists of a variable mixture 
of acid calcium arsenate, CaHAs04, and basic calcium arsenate, 
Ca3(As04)2. It is sold in two forms — a thick paste and a 
powder. It may be used as a substitute for arsenate of lead 
and is considerably cheaper. Unfortunately, when used alone 
there is some danger of burning the foliage. This may be 
overcome by adding an equal weight of quicklime, or by using 
it with bordeaux mixture. Calcium arsenate contains a larger 
percentage of arsenic than arsenate of lead and it is, there- 
fore, not necessary to use so large a quantity. 

Hellebore. 

Hellebore is a light brown powder made from the roots of 
the white hellebore plant {Veratrum album), one of the lily 
family. It is applied both dry and in water. In the dry 
state, it is usually applied without dilution, although the ad- 
dition of a little flour will render it more adhesive. In water, 



INSECTS AND INSECTICIDES 373 

4 ounces of the poison are mixed with 2 or 3 gallons, and an 
ounce of glue, or thin flour paste, is sometimes added to make 
it adhere. A decoction is made by using boiling water in the 
same proportions. Hellebore soon loses its strength, and a 
fresh article should always be demanded. It is much less 
poisonous than the arsenicals, and, therefore, may be used on 
vegetables soon to be eaten. It is of especial value in the home 
garden. 

Soaps. 

Soap solutions are often used as contact insecticides for 
killing plant-lice and other small, soft-bodied insects. The 
so-called whale-oil or fish-oil soaps are most widely used for 
this purpose. The commercial brands are usually by-products 
and contain many impurities ; furthermore, many of them 
contain an excess of free or uncombined alkali and are con- 
sequently very likely to injure young and tender foliage. An 
excellent fish-oil soap may be easily prepared at home by the 
following formula : 

Caustic soda pounds 

Water i gallon 

Fish-oil 22 pounds 

Completely dissolve the caustic soda in the water, and then 
add the fish-oil very gradually under constant and vigorous 
stirring. The combination occurs readily at ordinary summer 
temperatures and boiling is unnecessary. Stir briskly for about 
twenty minutes after the last of the oil has been added. 

Sulfur. 

Sulfur is commonly sold in two forms, — flowers of sulfur 
and flour of sulfur. Flowers of sulfur or sublimed sulfur is a 
fine, impalpable yellow powder insoluble in water, and is 
formed by condensing sulfur vapor in a. large chamber of brick 



374 MANUAL OF VEGETABLE-GARDEN INSECTS 

work. If the sulfur vapor is condensed to the liquid form in 
a cold receiver, roll sulfur is formed. Flour of sulfur is made 
by grinding roll sulfur to a fine powder. 

In the form of a powder or dust, sulfur is especially valuable 
against red-spider. For this purpose it is often diluted with 
hydrated lime and may be applied mixed w^ith water at the 
rate of 1 pound in 3 gallons, in which a little soap has been 
dissolved to help keep the sulfur in suspension. The sulfur 
settles quickly and should be agitated constantly during spray- 
ing. The sulfur will remain in suspension longer if first made 
into a paste with water containing i of one per cent of glue. 

Emulsions. 

Emulsions are sprays in which oils are suspended in water 
in the form of minute globules, a condition brought about by 
the addition of soap. They form an important class of contact 
insecticides useful particularly against plant-lice and other 
soft-bodied insects. 

Kerosene emulsion is one of the oldest of contact insecticides. 
It is prepared by the following formula : 

Soap i pound 

Water 1 gallon 

Kerosene 2 gallons 

Dissolve the soap in hot water; remove from the fire and 
while still hot add the kerosene. Pump the liquid back into 
itself for five or ten minutes or until it becomes a creamy mass. 
If properly made the oil will not separate on cooling. 

For killing plant-lice on foliage, dilute with 10 to 15 parts 
of water. The strength of oil emulsions is frequently indicated 
by the percentage of oil in the diluted liquid : 

For a 10 per cent emulsion add 17 gal. water to 3 gal. stock emulsion. 
For a 15 per cent emulsion add 10^ gal. water to 3 gal. stock emulsion. 
For a 20 per cent emulsion add 7 gal. water to 3 gal. stock emulsion. 
For a 25 per cent emulsio;i add 5 gal. water to 3 gal. stock emulsion. 



INSECTS AND INSECTICIDES 375 

Carbolic acid emulsion is sometimes used against root- 
maggots. 

Soap 1 pound 

Water 1 gallon 

Crude carbolic acid 1 pint 

The soap is dissolved in hot water, the crude carbolic acid is 
added and the mixture is agitated into an emulsion. For use 
against root-maggots, this stock solution should be diluted with 
30 parts of water. 

Tobacco. 

Tobacco is one of the most useful insecticides. The poisonous 
principle in tobacco is an alkaloid, nicotine, which in the pure 
state is a colorless oily fluid, slightly heavier than water, of 
little smell when cold and with an exceedingly acrid burning 
taste even when largely diluted. It is soluble in water and 
entirely volatile. It is one of the most virulent poisons known ; 
a single drop is sufficient to kill a dog. 

Commercial tobacco preparations have been on the market 
for many years. The most important of these are "Black 
Leaf 40" and Xicofume. 

"Black Leaf 40" is a concentrated tobacco extract contain- 
ing 40 per cent nicotine in the form of nicotine sulfate. Its 
specific gravity is about L25. In this preparation the nicotine 
is in a non-volatile form, it having been treated with sulfuric 
acid to form the sulfate. "Black Leaf 40" is used at strengths 
varying from 1 part in 500 parts of water to 1 part in 1600 
parts. It can be satisfactorily combined with other sprays, 
as, for instance, bordeaux mixture, arsenate of lead and the 
various soap solutions. When used with water, 4 to 8 pounds 
of soap should be added to each 100 gallons to make the mixture 
spread and stick better. 

Nicofume is a tobacco extract containing 40 per cent of 



376 MANUAL OF VEGETABLE-GARDEN INSECTS 

nicotine in the volatile form. It is intended primarily for use 
in greenhouses. Strips of paper soaked in this preparation are 
smudged in greenhouses to destroy aphids. 

Tobacco is also used in the form of a dust for the same pur- 
pose. It is especially valuable against root-lice on asters and 
other plants. Tobacco extracts can be made at home by 
steeping tobacco stems in water, but as they vary greatly in 
nicotine content and are sometimes likely to injure tender 
foliage, it is better to buy the standardized extracts. 

Bordeaux mixture. 

Bordeaux mixture is widely used on potatoes and many 
other plants for the prevention of fungous diseases. In addi- 
tion to its fungicidal properties, it also acts as a deterrent to 
many insects, especially flea-beetles. Arsenate of lead, paris 
green and " Black Leaf 40 " may be used in combination 
with it. 

Bordeaux mixture is prepared by mixing a solution of copper 
sulfate, CUSO4, and milk of lime (calcium hydroxid) according 
to the following formula : 

Copper sulfate 4 pounds 

Lime 4 pounds 

Water '.50 gallons 

In some cases a weaker mixture is used, containing 3 pounds 
of copper sulfate and lime respectively. These formulas are 
often abbreviated thus : 4-4-50 and 3-3-50. 

When needed in large quantities, bordeaux mixture is most 
conveniently prepared by using stock solutions of copper 
sulfate and milk of lime and storing them in tubs on an elevated 
platform from which the desired quantity of each can be easily 
drawn off into the spray tank. 

The required quantity of copper sulfate slijuld be dissolved 
in water in the proportion of one pound to one gallon. This 



INSECTS AND INSECTICIDES 377 

may be most easily accomplished by suspending the copper 
sulfate crystals in a sack near the top of the water. A solution 
of copper sulfate is heavier than water. As soon, then, as the 
crystals begin to dissolve, the solution will sink, bringing 
water again in contact with the crystals. In this way, the 
crystals will dissolve much sooner than if placed in the bottom 
of the barrel. In case large quantities of stock solution are 
needed, two pounds of copper sulfate may be dissolved in each 
gallon of water, making the stock solution twice as strong. 

Slake the required quantity of lime in a tub or trough. Add 
the water slowly at first, so that the lime crumbles into a fine 
powder. If small quantities of lime are used, hot water is 
preferred. When completely slaked or entirely powdered, 
add more water. When the lime has slaked sufficiently, add 
water to bring it to a thick milk or to a certain number of gal- 
lons. The amount required for each tank of spray can be 
secured approximately from this stock mixture, which should 
not be allowed to dry out. Hydrated or prepared lime of 
good quality may be substituted for the stone lime. Place 
the required quantity in the barrel or tank and add water. 
No slaking is required. Do not use air-slaked lime. 

To make a 5-5-50 bordeaux mixture, take 5 gallons of stock 
solution, containing one pound of copper sulfate to a gallon 
(or one half as much of the stronger solution) for every 50 
gallons of bordeaux mixture required. Pour this into the 
spray-tank. Add water until the tank is about two thirds full. 
From the stock lime mixture add the required quantity. Stir 
the mixture and add water to make 50 gallons. Experiment 
stations often recommend the diluting of both the copper sul- 
fate solution and the lime mixture to one half the required 
amount before putting them together. This is not necessary, 
and is often impracticable for commercial work. It is preferable 
to dilute the copper sulfate solution. Never pour together 
the concentrated stock mixtures and dilute afterward. Bor- 



378 MANUAL OF VEGETABLE-GARDEN INSECTS 

deaux mixture of other strengths as recommended is made in 
the same way, except that the amounts of copper sulfate and 
lime are varied according to the requirements. 

It is not necessary to weigh the lime in making bordeaux 
mixture, for a simple test can be used to determine when enough 
of a stock lime mixture has been added. Dissolve an ounce of 
yellow prussiate of potash in a pint of water and label it 
"poison." Cut a V-shaped slit in one side of the cork so that 
the liquid may be poured out in drops. Add the lime mixture 
to the diluted copper sulfate solution until the ferrocyanid 
test solution icill not tvrn brown when dropped from the bottle 
into the mixture. It is always best to add a slight excess of 
lime. 

Sticker. 

The foliage of onions, cabbage and some other plants is so 
smooth that it is difficult to make a spray adhere to it. The 
following preparation will be useful for this purpose : 

Resin 2 pounds 

Sal soda (crystals) 1 pound 

Water 1 gallon 

Boil in an iron kettle in the open one to one and one half 
hours, or until the liquid takes on a clear brown color. Add 
this amount to each 50 gallons of bordeaux mixture. 

Fumigation. 

Two gases are in common use for killing insects, hydro- 
cyanic acid gas and carbon bisulfid. The former is much used 
for the destruction of vermin in houses, for fumigating nursery 
stock and for the destruction of greenhouse insects, particularly 
the white-fly and plant-lice. The latter is more generally used 
for killing insects infesting seeds and tubers in storage. 

Hydrocyanic acid gas is generated by placing either potas- 
sium cyanid (KCN) or sodium cyanid (NaCN) in dilute sul- 



INSECTS AND INSECTICIDES 379 

furic acid. The ingivdients are eombiiied in tlie following 
proportions : 

Potassium cyanid (98 per cent) . 1 ounce avoirdupois 

Sulfuric acid 1 fluid ounce 

Water 3 fluid ounces 

Potassium cyanid is a white, deliquescent, highly poisonous 
substance. The commercial article is usually in the form of 
rather hard irregular lumps which are readily soluble in water. 
Because of its tendency to draw moisture from the air, it is 
usually sold in tight tin cans or drums. Small amounts may 
be kept in glass fruit-jars. For fumigation purposes, only 
potassium cyanid that is at least 98 per cent pure should be 
used. 

The sulfuric acid need not be chemically pure, a good com- 
mercial grade being entirely satisfactory. 

When sodium cyanid is used, the proportions are as follows : 

Sodium cyanid 1 ounce avoirdupois 

Sulfuric acid 1| fluid ounces 

Water 2 fluid ounces 

When pure, sodium cyanid contains 53 per cent cyanogen 
(CX), which is about 33 per cent more than is present in potas- 
sium cyanid. It is customary to indicate the strength of sodium 
cyanid in terms of potassium cyanid ; that is, pure sodium 
cyanid is said to be 133 per cent pure. This means that 100 
pounds of sodium cyanid will yield as much cyanogen as 133 
pounds of potassium cyanid. For fumigation purposes, sodium 
cyanid should be at least 124 per cent pure and should not 
contain more than one per cent of common salt, as its presence 
causes the decomposition of the hydrocyanic acid gas. Owing 
to its higher cyanogen content, only three fourths as much 
sodium cyanid is required for fumigating a given space as of 
potassium cyanid. 



380 MANUAL OF VEGETABLE-GARDEN INSECTS 

In generating the gas, the proper procedure is to place the 
water in an earthen jar of suitable size. Butter crocks are 
convenient for this purpose. The acid is then added to the 
water, generating considerable heat. The w^ater should never 
be poured into the acid, since the steam produced will cause a 
vigorous bubbling and the acid may be spattered on the operator. 
After the acid has mixed with the water, the proper quantity 
of cyanid is placed in the liquid. The rapidity with which the 
gas is generated will depend on the temperature of the liquid 
and on the size of the lumps of cyanid. 

For destroying white-fly on tomatoes and cucumbers grown 
under glass, potassium cyanid should be used at the rate of 1 
ounce (or sodium cyanid, f ounce) to 3000 cubic feet of space 
contained in the house and the fumigation should continue 
all night. Fumigate only on dark dry nights when there is no 
wind. The house should be as dry as practicable and the 
temperature not above 60 degrees F. 

Carbon bisulfid is often used for fumigating peas and beans 
infested with weevils and potatoes infested with the tuber- 
moth. Carbon bisulfid (CS2) is a thin liquid that volatilizes 
at a low temperature, the vapor being very destructive to 
animal life. It is very inflammable and care should be taken 
not to bring it in contact with fire or with a lighted lamp. 
One should not smoke while fumigating. In fumigating peas 
and beans infested with weevils the seed should be placed in a 
tight box or barrel to which a cover has been fitted as nearly 
air-tight as possible. Carbon bisulfid is used at the rate of ^ 
to 1 ounce a bushel. In larger quantities in specially con- 
structed fumigating chambers, the weevils can be killed by 
using the liquid at the rate of 3 pounds to 1000 cubic feet. The 
material is placed in a shallow dish on the top of the seed. The 
box should then be covered tightly and the fumigation con- 
tinued for twenty-four to thirty-six hours. 

In fumigating potatoes to destroy the tuber-moth, the 



INSECTS AND INSECTICIDES 381 

material should be placed in tight bins lined with tarred paper 
and with the seams painted. The carbon bisulfid is used at 
the rate of 2 pounds for each 1000 cubic feet and the fumigation 
is continued for forty-eight hours. 

The carbon bisulfid is placed in shallow tin pans on top of 
the material to be treated. The vapor is heavier than air and 
will be gradually diffused through the mass. Fumigation with 
this material is more effective if the temperature is kept near 
70 degrees F. At lower temperatures the insects are less active 
and much more difficult to kill. 



INDEX 



A cidia fralria , 199. 
acrcea, Entigmenc, 359. 
Acroslernuni hilaris, 42. 
Adelphocoris rapidus, 195. 
adonidis, Enlomoscelis, 50. 
adusta, Scaptomyza, 45. 
aenea, Chwtopsis, 249. 
ceruginosa, Phcedon, 258. 
agonus, Limonius, 173. 
agrestis, Agriolimax, 354. 
agrejtis, Chorizagrotis, 287. 
Agriolimax agrestis, 354. 

cainpestris, 357. 
Agriotes mancus, 348. 
Agromyza maura simplex, 208. 

pusilla, 46. 

simplex, 208. 
Agrotis ypsilon, 205. 
albida, Macrobasis, 309. 
albilinea, Leucania, 298. 
allcrnata, Rhynchagrotis, 298. 
Anasa andrewsi, 120. 

armigera, 119. 

tristis, 116. 
andrewsi, Anasa, 120. 
annexa, Feltia, 273. 
yl«o/nis erosa, 253. 
Anthonomus eugenii, 255. 
Aphis brassiccE, 22. 

gossypii, 135. 

maidi-radicis, 218. 

pseudobrassicoe, 27. 

rumicis, 76. 
Apple leafhopper, 154. 
arctica, Hadena, 281. 
argus, Chelymorpha, 238. 
Argus tortoise beetle, 238. 
armigera, A nana, 119. 
armoracia, Plulella, 14. 
armoracice, Phylloireta, 328. 



Arrny cutworm, 287. 
.'Vrmy-worm, 288. 
Army-worms, 260. 
Arsenate of lead, 370. 
Arsenic, 369. 

Ash-gray blister-beetle, 306. 
asparagi, Crioceris, 201. 
asparagi, Tetrastichus, 204. 
Asparagus insects, 201. 

miner, 208. 
atomaris, Paragroiis, 298. 
Autographa bi-assiccB, 8. 

falcigera, 191. 
auxiliaris, Chorizagrotis, 287. 

B 

balteala, Diabrotica, 115. 
Barred-winged onion fly, 249. 
basaiis, Hemiglyptus, 326. 
Bean aphis, 76. 

insects, 54. 

ladybird, 67. 

leaf-beetle, 65. 

leaf-roller, 81. 

thrips, 69. 

weevil, 57. 
Beet army- worm, 294. 

insects, 90. 

leafhopper, 92. 
Belted cucumber beetle, 115. 
Bemisia inconspicua, 242. 
6p/<b, Pctnphigus, 102. 
bicolor. Coptocycla, 237. 
bipunctalis, Pachyzancla, 101. 
bipustulata, Phylloireta, 326. 
Bisulfid of carbon, 380. 
bivittata, Cassida, 236. 
Black army cutworm, 275. 
Black blister-beetle, 307. 
Black Leaf 40, 375. 
Black-legged tortoise beetle, 237. 



383 



384 



INDEX 



Black onion fly, 250. 
Black swallow-tail butterfly, 186. 
blanda, Systcna, 321. 
Blister-beetles, 302. 
Bordeaux mixture, 376. 
borealis, Epilachna, 133. 
brachyurus, Mancasellus, 257. 
brassicae. Aphis, 22. 
brassiccB, Autographa, 8. 
brassiccE, Phorbia, 29. 
Breathing of insects, 364. 
brevicornis, Tychea, 104. 
Bristly cutworm, 285. 
Broad bean weevil, 60. 
Bronzed cutworm, 286. 
Brown fruit-chafer, 23 L 
Bruchus chinensis, 63. 

obtectus, 57. 

pisorum, 54. 

quadrimaculatus, 61. 

rufimanus, 60. 
brunnea, Colaspis, 67. 
Burdock borer, 160. 



Cabbage aphis, 22. 

curculio, 49. 

iiisects, 3. 

leaf-miners, 43. 

looper, 8. 

root-maggot, 29. 

seed-stalk weevil, 50. 

webworm, 16. 
Calcium arsenate, 372. 
Calico-back, 38. 
calif or nicus, Limonius, 349. 
campestris, Agriol\m.ax, 357. 
Cantharis nuttalli, 308. 
Caradrina exigua, 294. 

flavimaculata, 294. 
Carbolic acid emulsion, 375. 
Carbon bisulfid, 380. 
Carrot beetle, 185. 

insects, 181. 

rust-fly, 181. 
Cassida bivittata, 236. 

nigripes, 237. 

pallidula, 177. 
cataphracta, Papaipema, 160. 



Celery insects, 181. 

leaf-tyer, 189. 

looper, 191. 
ceparum, Phorbia, 243. 
cerina, Glyptina, 319. 
Cerotoma trif areata, 65. 
Ceutorhynchus quadridens, 50. 

rapoe, 49. 
Chatocnema confinis, 332. 

ectypa, 334. 
Chatopsis aenea, 249. 
Chelyrnorpha argus, 238. 
Chewing insects, 363. 
chinensis, Bruchus, 63. 
Chorizagrotis agrestis, 287. 

auxiliaris, 287. 

introferens, 287. 
cinerea, E:picauta, 306. 
cinereola, Ogdoconta, 83. 
citri, HaUicus, 77. 
vbidopJithirus, Eriophyes, 174. 
clundrstina, Noctua, 263. 
Clay-backed cutworm, 274. 
Clover cutworm, 284. 
c-nigrum, Noctua, 262. 
cceruleocinctus , Julus, 344. 
Colaspis brunnea, 67. 
Colorado corn root-worm, 227. 

potato beetle, 142. 
Common asparagus beetle; 201. 

stalk-borer, 157. 
communis, Melanotua, 349. 
concavus, Lixns, 251. 
confinis, Chcetocnema, 332. 
Confused wireworm, 349. 
confusus, Limonius, 349. 
connexa, Diabrotica, 116. 
consputa, Monoxia, 96. 
Coptocycla bicolor, 237. 

signifera, 238. 
Corn and cotton wireworm, 349. 

ear- worm, 211. 

insects, 211. 

root-aphis, 218. 

wireworm, 349. 
corrupta, Epilachna, 67. 
corvina, Epicauta, 311. 
Cowpea weevil, 63. 
crenicollis, Disonycha, 332. 
Crioceris asparagi, 201. 



INDEX 



385 



Crioceris — Cont. 

duocicchn pu7u-tata. 205. 

qiiatiiordcri ni punctata, 207. 

quinquc punctata, 207. 
Cross-striped cabbage worm, 14. 
Crow blister-beetle, .311. 
Cucumber flea-beetle, 314. 

insects, 109. 
cucumeris, Epitrix, 314. 
cucurbitoe, Macrosiphum, 139. 
Cutworms, 260. 
Cyanid of potassium, 379. 

of sodium, 379. 
Cylas formicarius, 239. 

D 

Dargida procinctus, 298. 
Dark-sided cutworm, 268. 
decemlineata, Leptinotama, 142. 
Depressaria heracliana, 197. 
Desert corn flea-beetle, 334. 
detersa, Paraorotis, 298. 
devasiatrix, Hadena, 279. 
Development of insects, 365. 
Diabrotica halteata, 115. 
connexa, 116. 

duodecim punctata, 113, 222. 
longicornis, 225. 
soror, 114. 
trivittata, 113. 
tirgifera, 227. 
rittata, 109. 
Diacrisia virginica. 357. 
Diamond-back moth, 12. 
Diaphania hyalinata, 131. 

nitidalis, 127. 
Diatrcea zeacolella, 228. 
Dingy cutworm, 271. 
Disonycha crenicollis, 332. 
mellicollis, 331. 
triangularis, 331. 
xanthomelaena. 329. 
ducens, Feltia, 271. 
duodecim punctata, Crioceris, 205. 
duodecim punctata, Diabrotica, 113, 

E 

Eastern field wireworm, 173. 
ectypa, Chcetocnema, 334. 

2c 



Eggplant flea-beetle, 320. 
insects, 177. 
lace-bug, 178. 
tortoise beetle, 177. 
Elasmopalpus lignoselius, 229. 
Empoasca mali, 154. 
Emulsions, 374. 
Entomoscelis adonidis. 50. 
Epicauta cinerea, 306. 
corvina, 311. 
lemniscata, 303. 
maculata, 309. 
marginata, 305. 
pardalis, 311. 
pennsylvanica, 307. 
r7:«a<a, 302. 
Epilachna borealis, 133. 

corrupta, 67. 
Epitrix cucumeris, 314. 
fuscula, 320. 
parvula, 319. 
subscrinita, 318. 
criccB, Nysius, 47. 
eridania. Pi-ode nia, 297. 
Erinose of the tomato, 174. 
Eriophyes cladophthirus, 174. 
erosa, Anomis, 2.53. 
FJistigmenc acraea, 359. 
Eudamus protcus, 81. 
eugenii, Anthonomus, 255. 
Euphoria inda, 231. 
euschistoides, Euschistus, 232. 
Euschistus euschistoides, 232. 

variolarius, 232. 
Eutettix tenellus, 92. 
Evergestis rimosalis, 14. 

straminalis, 19. 
exigua, Caradrina, 294. 



falcigei-a, Autographa, 191. 
Fall army-worm, 292. 
False chinch-bug, 47. 
fascialis, Hymenia, 99. 
fasciatus, Heliothrips, 69. 
Feeding of insects, 363. 
Feltia annexa, 273. 

ducens, 271. 

gladiaria, 274. 



386 



INDEX 



Feltia — Cont. 

jacuUfera, 271. 

nialejida, 'll'I. 

subgothica, 271. 

venerabiLis, 298. 
fennica, Noctua, 275. 
ferrugalis, PhhjctcBnia, 189. 
Five-spotted asparagus beetle, 207. 
Fire-bug, 38. 
Fish-oil soap, .373. 
flaveola, Scaptomyzn, 44. 
flavimaculata, Caradrina, 294. 
Flea-beetles, 313. 
flexa, Triloxa, 250. 
formicarius, Cylas, 239. 
Four-spotted bean weevil, Gl. 

cabbage flea-beetle, 32G. 
Fourteen-spotted asparagus 

207. 
fratria, Acidia, 199. 
frontalis, Systena, 323. 
frugiperda, Laphygma, 292. 
Fumigation, 378. 
fiisciceps, Phorbia, 36. 
fuscula, Epitrix, 320. 



G 



beetle. 



Garden flea-hopper, 77. 
Garden springtail, 139. 

webworm, 18. 
Gargaphia solani, 178. 
gibbosus, Ligyrus, 185. 
gladiaria, Feltia, 274. 
Glassy cutworm, 279. 
Glyptina cerina, 319. 
Golden tortoise beetle, 237. 
gossypii. Aphis, 135. 
gracilis, Orlhomorpha, .343. 
graminum, scaptomyza, 45. 
graminum, Toxoptera, 135. 
Granulated cutworm, 273. 
(irape colaspis, 67. 
Grapholita nigricana, 79. 
Grasshoppers, 350. 
Grass-worm, 292. 
Gray blister-beetle, .306. 
Gray field slug, 354. 
Gray hair-streak, 84. 
Greasy cutworm, 265. 



Green clover worm, 85. 
Greenhouse millipede, 343. 
Green soldier-bug, 42. 

H 

Hadena arctica, 281. 

devastatrix, 279. 
Halticus cilri, 77. 
Harlequin cabbage bug, 38. 
Hawaiian beet webworm, 99. 
Heliophila unipuncta, 288. 
Hcliofhis obsolete, 211. 
Heliothrips fasciatus, 69. 
Hellebore, 372. 
Hellula undalis, 16. 
Hemiglyptus basalis, 326. 
heracliana, Deprcssaria, 197. 
Heterodera radicicola, 3.38. ' 

schactii, 342. 
hilaris, Acrosternurn, 42. 
lurticula, Lachnosterna, 345. 
histrionica, Murgantia, 38. 
Hop flea-beetle, 335. 
Horistonotus uhlerii, .349. 
Horned squash bug, 119. 
Horse-radish flea-beetle, 328. 
hortensis, Sminthurus, 139. 
hudsonias, Systena, .323. 
hyalinata, Diaphania, 131. 
Hydrocyanic acid gas, 378. 
Hyjnenia fascialis, 99. 

perspectalis, 100. 
hyoscyami, Pcgomyia, 90. 

I 

Idiocerus scurra, 367. 
iiicis, Lachnosterna, 345. 
immaculata, Macrobasis, 310. 
Iinniaculate blister-beetle, 310. 
Imi)orted cajjbago leaf-miner, 45. 

cal)bage worm, 4. 

turnip leaf-miner, 44. 
inconspicua, Bcmisia, 242. 
inda, Euphoria, 231. 
Insecticides, 36<S. 
insperata, Lytin, 311. 
insulsa, Parugrotis, 298. 
introfcrens, Chorizagrotis, 287. 



INDEX 



jaculifera, Feltia, 271. 
Jalysus spinosus, 172. 
Julus caeridcocinctus, .344. 



Kerosene emulsion, .374. 



Lachnoatrrna hirticula, .34.5. 

ilicis, 34.5. 
lactucce, Rhizohius, 258. 
Laphygma frugiperda, 292. 
Lapping insects, 364. 
Large black blister-beetle, 311. 
Larger corn stalk-borer, 228. 

striped flea-beetle, 332. 

sugar-beet leaf-beetle, 9.5. 
laliusculus, Listronotus, 199. 
Load arsenate, 370. 
Irgitima, Mamestra, 22. 
Lema nigrovittata, 149. 

trilineata, 149. 
Jrtnniscata, Epicauta, 303. 
Leptinotarsa dccrmlinrala, 142. 
Lcptoglossus oppositus, 122. 

phyllopus, 121. 
Lesser corn stalk-borer, 229. 
Lettuce insects, 258. 

root-louse, 258. 
Lcucania alhilinea, 298. 

unipuncta, 288. 
Ugnosellus, Elasmopalpus, 229. 
Ligyrus gibbosus, 18.5. 
Lima bean vine-borer, 87. 
Limonius agonus, 173. 

calif ornicus , 349. 

confusus, 349. 
Listronotus latiusculus, 199. 
iividus, Monocrepidius, 347. 
Lixus concavxis, 251. 
London purple, 370. 
longicollis, Macrobasis, 310. 
longicornis, Diabrotica, 225. 
Losses caused by insects, 1. 
Loxostege similalis, 18. 

sticticalis, 97. 
Lygus pratenxis, 192. 
Lf/i/a inspcrata, 311. 



M 

Macrobasis alhida, 309. 

immacidala, 310. 

longicollis, 310. 

segmentata, .310. 

uidcolor, 306. 
Macrosiphum cucurbitw, 139. 

pwi, 71. 

solanifolii, 150*. 
maculata, Epicauta, .309. 
maculipennis, Plutella, 12. 
maidi-radicis. Aphis, 218. 
malefida, Feltia, 272. 
ma/i, Empoasca, 154. 
Mamrstra picta, 21. 

IcgiliiiKi, 22. 

rrnigcra, 285. 

subjuncta, 283. 

trifolii, 284. 
Mancasellus brachyurus, 257. 
mancus, Agriotes, 348. 
margaritosa, Peridroma, 276. 
marginata, Epicauta, 305. 
Margined blister-beetle, 305. 
Mclanotus communis, 349. 
melinus, Uranotes, 84. 
Mclitia salyriniformis, 124. 
mellicollis, Disonycha, .331. 
Melon aphis, 135. 

insects, 109. 

leaf-bug, 121. 

worm, 131. 
mcssoria, Paragrotis, 268. 
Metamorphosis of insects, 366. 
Millipedes, .342. 
minians, Nephelodcs, 286. 
niinutius, Nysius, 48. 
Monocrepidius Iividus, 347. 
Monoptilota nubilella, 87. 
M anoxia consputa, 96. 

puncticollis, 95. 
Mottled tortoise beetle, 238. 
Murgantia histrionica, 38. 
Myzus persicce, 105. 

N 

Native cabbage leaf-miner, 45. 
nchris, Papaipema, 160. 
Negro-bug, 196. 



388 



INDEX 



Nephelodes minians, 286. 
Nezara viridula, 43. 
Nicofume, 375. 
nioricana, Grapholita, 79. 
nigripcs, Cassida, 237. 
nigromttata, Lerna, 149. 
nitela, Papaipema, 157. 
nitidalis, Diaphania, 127. 
Noctua clandestina, 263. 

c-nigrum, 262. 

fcnnica, 275. 
Northern leaf-footed plant-buc 

tomato worm, 169. 
nubilella, Munoptilota, 87. 
nuttalii, Canlharia, 308. 
Nuttall's blister-beetle, 308. 
Nysius ericce, 47. 

minuius, 48. 

O 

obsoleta, Heliothis, 211. 
ohtectus, Bruchus, 57. 
ochrogaster, Paragrotis, 267. 
Ogdoconta cinereola, 83. 
Okra caterpillar, 253. 

insects, 253. 
oleracea, Pontin, 7. 
Onion insects, 243. 

maggot, 243. 

thrips, 245. 
operculella, Phthorimcea, 162. 
oppositus, Leptoglossus, 122. 
ornithogalli, Prodenia, 295. 
orthogonia Porosagrotis, 298. 
Orthomorpha gracilis, 343. 



Pachyzancla hipunclalis, 101. 
Pale-striped flea-beetle, 321. 
pallidula, Cassida, 177. 
Panther blister-beetle, 311. 
Papaipema cataphracta, 160. 

nebris, 160. 

nitela, 157. 
Papilio polyxcnes, 186. 

zolicaon, 1(S9. 
Paragrotis atomaris, 298. 

detersa, 298. 

insulsa, 298. 



122. 



Paragrotis — Cont. 
mrssoria, 268. 
ochrogaster, 267. 
perexcellens, 298. 
scandens, 278. 
tcssellata, 270. 
pardalis, Epicauta, 311. 
Paris green, 369. 
Parsley stalk-weevil, 199. 
Parsnip insects, 181. 
leaf-miner, 199. 
wobworm, 197. 
parvula, Epitrix, 319. 
Pea aphis, 71. 
insects, 54. 
moth, 79. 
weevil, 54. 
Pegomyia hyoscyami, 90. 
Pemphigus betcB, 102. 
pennsylvanica, Epicauta, 307. 
Pepper insects, 255. 

weevil, 255. 
perexcellens, Paragrotis, 298. 
Peridroma margaritosa, 276. 
persiccE, Myzus, 105. 
perspcctalis, Hymenia, 100. 
Phcedon aeruginosa, 258. 
phaseoli, Tychea, 104. 
Phlegethontius quinqucmaculata, 169. 

sexta, 171.' 
Phlyctcenia ferrugalis, 189. 
Phorbia brassica, 29. 
ceparum, 243. 
fusciceps, 36. 
planipalpis, 37. 
Phthorimcea operculella, 162. 
phyllopus, Leptoglossus, 121. 
Phyllotreta armoracice, 328. 
bipustulata, 326. 
pusilla, 327. 
ramosa, 326. 
sinuata, 326. 
«y7/a/a, 324. 
Pickle worm, 127. 
picta, Mamestra, 21. 
Pilocrocis tripunctata, 241. 
pis?', Macrosiphum, 71. 
pisorum, Bruchus, 54. 
placida, Rhynchagrotis, 298. 
planipalpis, Phorbia, 37. 



INDEX 



389 



PlathypcJia scahra, 85. 
Ptutella armoracia, 14. 

inaculipennis, 12. 
Pnyxia scahici, 161. 
polyxenes, Papilio, 186. 
Pontia oleracra, 7. 

protodice, 7. 

rapcB, 4. 
Porosagrotis orthogonia, 29S. 

vetusta, 282. 
Potassium cj'anirl, oT!). 
Potato aphis, l.")(). 

flea-beetle, 314. 

insects, 142. 

scab gnat, 161. 

stalk-weevil, 155. 

tuber moth, 162. 
Potherb butterfly, 7. 
pratensis, Lyons, 1!)2. 
procinctus, Dargida, 208. 
Prodenia eridania, 297. 

ornithogalli, 295. 
proteus, Eudamu.s, 81. 
protodice, Pontia, 7. 
pseudobrassiccB, Aphis, 27. 
Psila roscE, 181. 
Psylliodes punctulata, .335. 
pulicarius, Thyreocoris, 19G. 
puncticollis, Monoxia, 95. 
punctulata, Psylliodes, 335. 
Purple-backed ('al)bay;e worm, 19. 
pusilla, Agromyza, 46. 
pusilla, Phyllotrcta, 327. 
Pycnoderes quadrimaculatus, 121. 

Q 

quadridens, Cculorhynchus, 50. 
quadrimaculatus, Bruchus, 61. 
quadrimaculatus, Pycnoderes, 121. 
quatuordecimpunctata, Crioccris, 207. 
quinquemaculata, Phlegcthontius, 169. 
quinque punctata, Crioceris, 207. 

R 

radicicola, Heterodera, 338. 
ramosa, Phyllolreta, 326. 
rapce, Ceutorhynchus, 49. 
rapce, Pontia, 4. 



rapidus, Adelphocoris, 195. 
Red-backed cutworm, 267. 
Red-headed flea-beetle, 323. 
Red-spider, 351. 
Red turnip beetle, 50. 
renigera, Mamestra, 285. 
Rhizobius lactuccB, 258. 
Rhubarb curculio, 251. 

insects, 251. 
Rhynrliagrotis altcrnata, 298. 

placida, 298. 
rimosalis , EvergcM is , 14. 
Root-knot nematode, 338. 
ro.sfE, Psila, 181. 
rufimanus, Bruchus, 60. 
rumicis, Aphis, 76. 

S 

Salsify insects, 255. 
Salt-marsh caterpillar, 359. 
satyriniformis, Melittia, 124. 
scahiei, Pnyxia, 161. 
scabra, Plathypena, 85. 
scandcns, Paragrotis, 278. 
Scaptomyza adusta, 45. 

flaveola, 44. 

graminum, 45. 
schactii, Heterodera, 342. 
scurra, Idiocerus, 367. 
Seed-corn maggot, 36. 
segmenlata, Macrobasis, 310. 
Segmented black blister-beetle, 310. 
Semi-tropical army-worm, 297. 
Serpentine leaf-miner, 46. 
sexta, Phlegcthontius, 171. 
Shagreened cutworm, 272. 
signifera, Coptocycla, 238. 
similalis, Loxostege, 18. 
simplex, Agromyza, 208. 
simplex, Agromyza maura, 208. 
sinuata, Phyllotrcta, 326. 
Sinuate-striped flea-beetle, 326. 
Slugs, 3.54. 

Smartweed flea-beetle, 323. 
Sminthurus hortensis, 139. 
Soaps, 373. 
Sodium arsenite, 369. 

cyanamid, 341. 

cyanid, 379. 



390 



INDEX 



solani, Gargaphia, 178. 
solanifolii, Macrosiphum, 150. 
soror, Diahroticn, 114. 
Southern cabbage butterflj", 7. 

beet webworm, 101. 

corn root-worm, 222. 

leaf-footed plant-bug, 121. 

tomato worm, 171. 
Spanish-fly, .302. 
Spefklcd cutwonn, 28.3. 
Spinach aijhis, 103. 

flca-l>cctlc, 329. 

insects, 90. 

leaf-miner, 90. 
spinosus, Jalysus, 172. 
Spotted blister-beetle, 309. 

cutworm, 262. 

beet webworm, 100. 
Spotted-legged cutworm, 282. 
Squash aphis, 139. 

bug, 116. 

insects, 109. 

ladybird, 133. 
Squash-vine borer, 124. 
Sticker, 378. 
sticticalis, Loxostcgc, 97. 
Stink-bugs, 232. 
straminalis, Evcrgesfis, 19. 
Striped blister-beetle, 302. 

cabbage flea-beetle, 324. 

cucumber beetle, 109. 

cutworm, 270. 

green bean caterpillar, 83. 

tortoise beetle, 236. 
Structure of insects, 361. 
subgofhica, Fcltia, 271. 
suhjuncta, Mamestra, 283. 
subscrinita, Epitrix, 318. 
Sucking insects, 364. 
Sugar-beet nematode, 342. 

root-louse, 102. 

webworm, 97. 

wireworm, 349. 
Sulfur, 373. 
Sweet potato flea-beetle, 332. 

insects, 235. 

leaf-roller, 241. 

weevil, 239. 

white-fly, 242. 
Systena blanda, 321. 



Systena — Cont. 
frontalis, 323. 
hudsonias, 323. 
tceniaia, 321. 



tuhaci, Thrips, 245. 
twniata, Syslcna, 321. 
Tarnished i)lant-bug, 192. 
txiariuis, Tclranychus, 351. 
tcnellus, Eulcttix, 92. 
Terrapin-bug, 38. 
tcsaellata, Paragrotis, 270. 
Tetranychus tclarius, 351. 
Tctrastichus asparagi, 204. 
Three-lined potato beetle, 149. 
Three-spotted flea-beetle, 331. 
Thrips tabaci, 245. 
Thyreocoris pulicarius, 190. 
Tobacco, 375. 

dust, 370. 

flea-beetle, 319. 
Tomato insects, 108. 

stilt-bug, 172. 

worms, 168. 
Tortoise beetles, 235. 
Toxopkra graminum, 135. 
triangularis, Disonyclia, 331. 
Trichobaris trinotata, 155. 
trifolii, Mamestra, 284. 
trifurcata, Cerotoma, 65. 
triiineata, Le^na, 149. 
trinotata, Trichobaris, 155. 
tripunctata, Pilocrocis, 241. 
tristis, A7iasa, 116. 
Tritoxa flexa, 250. 
trivittata, Diabrotica, 113. 
Turnip aphis, 27. 
Twelve-spotted asparagus beetle, 205. 

cucumber beetle, 113. 
Two-spotted blister-beetle, 309. 
Tychca breviconiis, 104. 

pha^eoli, 104. 

U 

uhlerii, Horisionotus, 349. 
undalis, Hellula, 16. 
unicolor, Macrobasis, 306. 



INDEX 



391 



unipiincta, Heliophila, 288. 
Uranutes meiinus, 84. 



Variegated cutworm, 27G. 
variolariuji, Euschixliis, 2.'J2. 
vencrahiiis, Feltia, 2!),S. 
vetusta, Porosagrotiii, 282. 
virgifcra, Diahrotica, 227. 
virginica, Diacrisia, 357. 
viridula, Nezara, 4;}. 
vittata, Diahrotica, lO'J. 
vittata, Epicauta, 302. 
vittata, Phijllotreta, 324. 

W 

Water-press insects, 257. 

leaf-beetle, 258. 

sowbuK, 257. 
Well-iiuirked cutworm, 203. 
Western army-worm, 287. 

liect leaf-beetle, 90. 

cabbage flea-beetle, 327. 

corn root-worm, 225. 

cucumber beetle, 113. 



Western potato flea-beetle, 318. 

radish maggot, 37. 

twelve-spotted cucumber beetle, 114. 
Whale-oil soap, 373. 
Wheat wireworm, .348. 
^^'hite cutworm, 278. 
White grubs, 344. 
\\'ireworms, 347. 

X 

xanthomelwna, Disonycha, 329. 



Y 

Yellow bear caterpillar, 357. 
Yellow-headed cutworm, 281. 
Yellow-necked flea-beetle, 331. 
Yellow-striped army-worm, 295. 
ypsilon, Agrotis, 265. 



zcacoldla, Diatrcea, 228. 
Zebra caterpillar, 21. 
Zinc arsenite, 372. 
zolicaon, Papilio, 189. 



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go wrong." — The Argonaut. 

The practical quality of this book, its unpretentiousness, will appeal to the amateur who is 
too frequently frightened away from a volume of this character by elaborate directions and the 
seeming necessity of expensive equipment. 



THE MACMILLAN COMPANY 

Publishers 64-66 Fifth Avenue New York 



THE RURAL MANUALS 

Edited by L. H. BAILEY 



Manual of Milk Products i:iustratcd,i2mo,%3.oo 

By VV. A. STOCKING, Jr. 

Manual of Fruit Diseases iut,strated,,2mo,i,2.oo 

By L. R. HESSLER and H. H. WHETZEL 

The Pruning Manual illustrated, i2mo, 407 pp. ,%2-oo 

By L. H. BAILEY 

Manual of Fruit Insects 

By MARK VERNON SLINGERLAND and CYRUS R. CROSBY 

Of the New York State College of Agriculture, at Cornell University 

Illustrated, 121110, ^oj pages, $2.00 

A Manual of Weeds 

By ADA E. GEORGIA 

Assistant in the Farm Course, New York State College of Agriculture, Cornell University 

With 385 Illustrations by F. SCHUYLER Mathews 

Illustrated, cloth, 127710, 59J pages, nidex, $2.00 

Manual of Farm Animals 

A Practical Guide to the Choosing, Breeding, and Keep of Horses, Cattle, 

Sheep, and Swine 

By MERRITT W. HARPER 

Assistant Professor of Animal Husbandry in the New York State College of Agriculture, 

at Cornell University 

Illustrated, i2mo, 5^5 pages, index, $2.00 

" A book deserving of close study as well as being handy for reference, and 
should be in the possession of every farmer interested in stock." — Rural World. 

Manual of Gardening 

A Practical Guide to the Making of Home Grounds and the Growing of 

Flowers, Fruits, and Vegetaisles for Home Use 

By L. H. BAILEY 

Illustrated, cloth, 127/10, j^^ pages, $2.00 

This new work is a combination and revision of the main parts of two other 
books by the same author, " tiarden-Making " antl " Practical (jarden Book," 
together with much new material and the result of the experience of ten added 
years. 

The Farm and Garden Rule Book 

By L. H. BAILEY 

Revised afid c/tlarged editio7t ; illustrated, cloth, 127110, $2.00 

It is essentially a small cyclopedia of ready rules and references packed full 
from cover to cover of condensed, meaty information and precepts on almost 
every leading subject connected with country life. 



THE MACMILLAN COMPANY 

Publishers 64-66 Fifth Avenue New York 



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